Update dependencies and config

[fregante]

Config mostly copied from https://github.com/sindresorhus/refined-github

Before

            background.js ⏤  3.31 kB
 hide-files-on-github.css ⏤  0 B (-636 B) <-- misconfig 
  hide-files-on-github.js ⏤  5.33 kB
              options.css ⏤  0 B (-413 B)
             options.html ⏤  0 B (-524 B)
               options.js ⏤  3.44 kB
          webext-base.css ⏤  0 B (-764 B)

After

            background.js ⏤  3.51 kB
 hide-files-on-github.css ⏤  636 B
  hide-files-on-github.js ⏤  5.21 kB
              options.css ⏤  413 B
             options.html ⏤  524 B
               options.js ⏤  3.37 kB
          webext-base.css ⏤  764 B