Bug: short subdomain length stops frontend loading

[Hiumee]

A short subdomain length will treat the /static path as a subdomain
The get_subdomain_from_path function usually returns None due to the / after those paths. With a subdomain length <= 6 the / character is not considered and passes the set(subdomain) - alphabet_set != set() check

[adrgs]

Good catch, thanks. Added public and api to reserved_keywords in config.py, such that they won't be overriden in the default case.
Fixed in #45

[Hiumee]

Still not fixed. static should be a keyword, other paths are affected like logo.svg
For a 4-letter domain, the line subdomain = path[:length] truncates the input from static to stat and fails the check
Something like subdomain = path[:subdomain.find('/')] when it contains / might be a better fix

[adrgs]

You're correct, it's static not public. Added it and a few others like logo, assets and favicon to keywords. I think that should be all.
Let me know if there's anything that I've missed in #49