Add Prettier, Eslint and Husky

[lipis]

This PR is fixing the #99 and it's splitted into two commits.. one for the settings and the one that formats the files.

Except .js files, this PR is also fixes the .json and .md files.

---

Some of the rules that could be added eventually.. :)

  id-length: 2
  no-magic-numbers: [2, {ignore: [-1, 0, 1]}]
  no-shadow: 2
  sort-keys: [2, asc, {caseSensitive: true, natural: true}]

---

Based on prettier-setup

[lipis]

Feel free to go through the .eslintrc.yaml and .prettierrc.yaml if you want add/remove/change anything...

[caiogondim]

That's a massive PR 😄

The only thing holding me from merging this PR is the use of ES6+ syntax, like const, let, arrow functions, ...
We have to keep compatibility with older browsers.

Other than that, let's do it 💪

[lipis]

I forgot about this one.. will come back to it over the weekend!

[caiogondim]

No worries. Let me know if you need some help.