[CLEANUP] Make Hedy PEP8 compliant (hedyorg#3602)

**Description**

Since hedyorg#3410 we introduced a git pre-commit hook to lint modified code. However, much of the Hedy codebase is still not PEP8 compliant, in this PR we'll change that by applying autopep8 to the whole codebase with the following parameters:

```
autopep8 --in-place --max-line-length 120  -aaa --jobs 0 [files]
```
A few changes have been made to the pre-commit hook:
* The max line length now is 120
* I excluded the max line check from utils.py  because the number dictionary is too long.

**Checklist**
Done? Check if you have it all in place using this list:*
  
- [ ] Describes changes in the format above (present tense)
- [ ] Links to an existing issue or discussion 
- [ ] Has a "How to test" section

If you're unsure about any of these, don't hesitate to ask. We're here to help!

CONTRIBUTING.md

@@ -102,10 +102,9 @@ bash feed_dev_database.sh
 ```
 
 ## Python code styling
-As this project is growing and multiple people are working on it, we want to move to a more uniformly styled code base. We choose to stick to PEP8 guidelines, with the exception of a max line length of 100 characters instead of 79. To ensure your code adheres to these guidelines, you can install the pre-commit configuration to automatically check modified code when you make a commit. Installing this pre-commit hook has to be done manually (for security reasons) and can be done using the following commands:
+As this project is growing and multiple people are working on it, we want to move to a more uniformly styled code base. We choose to stick to PEP8 guidelines, with the exception of a max line length of 120 characters instead of 79. To ensure your code adheres to these guidelines, you can install the pre-commit configuration to automatically check modified code when you make a commit. Installing this pre-commit hook has to be done manually (for security reasons) and can be done using the following commands. The pre-commit hook is available for installation once you run `requirements.txt`:
 
 ```
-pip install pre-commit
 pre-commit install
 ```
 

config.py

@@ -6,7 +6,7 @@
 athena_query = os.getenv('AWS_ATHENA_PREPARE_STATEMENT')
 
 config = {
-    'port': os.getenv ('PORT') or 8080,
+    'port': os.getenv('PORT') or 8080,
     'session': {
         'cookie_name': 'hedy',
         # in minutes
@@ -44,6 +44,6 @@
         's3_output': 's3://hedy-query-outputs/',
         'max_results': 50
     },
-    #enables the quiz environment by setting the config variable on True
+    # enables the quiz environment by setting the config variable on True
     'quiz-enabled': True,
 }

content/yaml_to_lark_utils.py

@@ -1,15 +1,16 @@
-from pathlib import Path
 import collections
 import copy
 import os
 import yaml
 
+
 def extract_Lark_grammar_from_yaml():
     """Creates a lark file in ../grammars/ for  all yaml files located in ../content/keywords/.
     If a keyword is not yet translated, it will use the English translation of the keyword
 
     Args:
-        only_new_lang (bool, optional): Specifies if only a lark file should be created for a new keyword language or for all languages. Defaults to True.
+        only_new_lang (bool, optional): Specifies if only a lark file should be created for a new keyword language
+        or for all languages. Defaults to True.
     """
     dirname = os.path.dirname(__file__)
     input_path = os.path.join(dirname, 'keywords')
@@ -44,11 +45,11 @@ def extract_Lark_grammar_from_yaml():
         translation_copy = copy.deepcopy(translations)
         for k, v in translation_copy.items():
             if yaml_lang == "ar":
-              mixed_tatweel_in = ''.join([' "ـ"* ' + '"'+l+'"' for l in v]) + ' "ـ"* '
-              translations[k] = mixed_tatweel_in
+                mixed_tatweel_in = ''.join([' "ـ"* ' + '"' + lang + '"' for lang in v]) + ' "ـ"* '
+                translations[k] = mixed_tatweel_in
             else:
-              # other languages need their translations surrounded by "'s
-              translations[k] = '"' + v + '"'
+                # other languages need their translations surrounded by "'s
+                translations[k] = '"' + v + '"'
 
             # we use | if we have multiple options, such as repete and repète
             if "|" in v:
@@ -64,6 +65,5 @@ def extract_Lark_grammar_from_yaml():
         with open(lark_filesname_with_path, 'w', encoding='utf-8') as f:
             f.write(translated_template)
 
-extract_Lark_grammar_from_yaml()
-
 
+extract_Lark_grammar_from_yaml()

docs.py

@@ -3,68 +3,71 @@
 import re
 import unicodedata
 
+
 def slugify(s):
-  if s is None:
-    return None
-  return re.sub('[^a-zA-Z0-9]', '-', strip_accents(s)).lower()
+    if s is None:
+        return None
+    return re.sub('[^a-zA-Z0-9]', '-', strip_accents(s)).lower()
 
 
 def strip_accents(s):
-  return ''.join(c for c in unicodedata.normalize('NFD', s)
-                 if unicodedata.category(c) != 'Mn')
+    return ''.join(c for c in unicodedata.normalize('NFD', s)
+                   if unicodedata.category(c) != 'Mn')
+
 
 class DocCollection:
-  def __init__(self, keys=[], synth={}):
-    self.docs = []
-    self.index = {}
-    self.keys = keys
-    self.synth = synth
-
-  def get(self, *keys):
-    v = self.index
-    for key in keys:
-      v = v.get(key)
-      if not v:
-        return {} if len(keys) < len(self.keys) else None
-    return v
-
-  def load_dir(self, rootdir):
-    files = glob.glob(f'{rootdir}/**/*.md', recursive=True)
-    for file in sorted(files):
-      doc = MarkdownDoc.from_file(file)
-
-      for k, v in self.synth.items():
-        doc.front_matter[k] = v(doc)
-
-      self.docs.append(doc)
-      self.add_to_index(doc)
-
-  def add_to_index(self, doc):
-    if not self.keys:
-      return
-
-    d = self.index
-    for key in self.keys[:-1]:
-      value = doc.front_matter.get(key, None)
-      if not value:
-        return
-      d = d.setdefault(value, {})
-
-    key = self.keys[-1]
-    value = doc.front_matter.get(key, None)
-    if value:
-      d[value] = doc
+    def __init__(self, keys=[], synth={}):
+        self.docs = []
+        self.index = {}
+        self.keys = keys
+        self.synth = synth
+
+    def get(self, *keys):
+        v = self.index
+        for key in keys:
+            v = v.get(key)
+            if not v:
+                return {} if len(keys) < len(self.keys) else None
+        return v
+
+    def load_dir(self, rootdir):
+        files = glob.glob(f'{rootdir}/**/*.md', recursive=True)
+        for file in sorted(files):
+            doc = MarkdownDoc.from_file(file)
+
+            for k, v in self.synth.items():
+                doc.front_matter[k] = v(doc)
+
+            self.docs.append(doc)
+            self.add_to_index(doc)
+
+    def add_to_index(self, doc):
+        if not self.keys:
+            return
+
+        d = self.index
+        for key in self.keys[:-1]:
+            value = doc.front_matter.get(key, None)
+            if not value:
+                return
+            d = d.setdefault(value, {})
+
+        key = self.keys[-1]
+        value = doc.front_matter.get(key, None)
+        if value:
+            d[value] = doc
+
 
 class MarkdownDoc:
-  @staticmethod
-  def from_file(filename):
-    with open(filename, 'r', encoding='utf-8') as f:
-      contents = f.read()
-    parts = re.split('^---+$', contents, maxsplit=1, flags=re.M)
-    if len(parts) == 1:
-      return MarkdownDoc({}, parts[0])
-    return MarkdownDoc(yaml.safe_load(parts[0]), parts[1])
-
-  def __init__(self, front_matter, doc):
-    self.front_matter = front_matter
-    self.markdown = doc
+    @staticmethod
+    def from_file(filename):
+        with open(filename, 'r', encoding='utf-8') as f:
+            contents = f.read()
+        parts = re.split('^---+$', contents, maxsplit=1, flags=re.M)
+        if len(parts) == 1:
+            return MarkdownDoc({}, parts[0])
+        return MarkdownDoc(yaml.safe_load(parts[0]), parts[1])
+
+    def __init__(self, front_matter, doc):
+        self.front_matter = front_matter
+        self.markdown = doc