Contributing guide (pytorch#1424)

* Add materials on how to setup dev env in CONTRIBUTING guide pytorch#1395
- first draft of first-time contributor guide

* Add materials on how to setup dev env in CONTRIBUTING guide pytorch#1395
- add in Table of Contents

* Add materials on how to setup dev env in CONTRIBUTING guide pytorch#1395
- fix table of contents link

* Add materials on how to setup dev env in CONTRIBUTING guide pytorch#1395
- rollback README.md, remove IDE setting

* Update CONTRIBUTING.md

Co-authored-by: Sylvain Desroziers <[email protected]>
Co-authored-by: vfdev <[email protected]>

CONTRIBUTING.md

@@ -29,6 +29,31 @@ If you find a typo in the documentation, do not hesitate to submit a GitHub pull
 
 ## Developing Ignite
 
+### Quickstart guide for first-time contributors
+
+<summary>
+
+<details>
+
+- Install [miniconda](https://docs.conda.io/projects/continuumio-conda/en/latest/user-guide/install/index.html) for your system.
+- Create an isolated conda environment for pytorch-ignite:
+ ```bash
+conda create -n pytorch-ignite-dev python=3
+```
+
+- Activate the newly created environment:
+ ```bash
+conda activate pytorch-ignite-dev
+```
+
+- When developing please take care of preserving `.gitignore` file and make use of `.git/info/exclude` to exclude custom files like: `.idea`, `.vscode` etc.
+- Please refer to [github first contributions guidelines](https://github.com/firstcontributions/first-contributions) and don't hesitate to ask the pytorch-ignite community in case of any doubt.
+- A good way to start is to tackle one of the [good first issues](https://github.com/pytorch/ignite/labels/good%20first%20issue).
+
+</details>
+
+</summary>
+
 ### Installation
 
 To get the development installation with the necessary dependencies, run the following:
@@ -175,4 +200,3 @@ python -m http.server <port>
 # python -m http.server 1234
 ```
 Then open the browser at `0.0.0.0:<port>` (e.g. `0.0.0.0:1234`) and click to `html` folder.
-