Fix CSS problems and other improvements

[rafaucau]

Changes proposed in this pull request:

• Update flarum webpack config, extract prettier config to .prettierc
• Use Flarum less variables instead of hardcoded colors - fixes #23
• [UX] Button tooltips telling the user what the button is for
• Social Profile permissions

Screenshot

Confirmed

• [x] Frontend changes: tested on a local Flarum installation.
• [x] Backend changes.

[rafaucau]

It was supposed to be a small PR with CSS fixes and what came out was a refractor of the whole extension 🤷‍♀️

[dsevillamartin]

I had not seen this PR, my bad. I'll incorporate your changes in a commit, thank you.

[dsevillamartin]

See https://github.com/FriendsOfFlarum/socialprofile/compare/78c1ded5758b...8f4fe3804302 🙂