* Add prettier as a dependency
* Add format command and configure prettier
I opted for single quotes to be in line with other simple-icons projects
I ignore the data file because changing its formatting is quite a bit of
trouble for all open PRs.
* Run prettier
* Replace all functions by arrow functions
* Move prettier configuration to config file
Move it to a file so editors (and other software) can pick up on the
configuration. I went with .js because (a) it allows for comments and
(2) it seems most of the config files are in JavaScript already.
* Add prettier --check when running npm run lint (This adds it to the CI as well)
* Add husky and format changes before committing
* Use object destructuring for imports consistently
* Add shebang and fileoverview to jsonlint.js
