feat: adding BRMangas provider

[saulojoab]

What kind of change does this PR introduce?

New PT-BR provider!

Did you add tests for your changes?

Yes.

If relevant, did you update the documentation?

Yes.

Summary

• Added a new Manga provider called BRMangas (provides brazilian-portuguese scans 🇧🇷)
• Added search, fetchMangaInfo and fetchChapterImages functions.

brmangas.search("punpun").then(data => {
  console.log(data);
})

brmangas.fetchMangaInfo("berserk-online").then(data => {
  console.log(data);
})

brmangas.fetchChapterPages("berserk-16-online").then(data => {
  console.log(data);
})

• Added test.
• Updated docs.

Other information
This one seems to be working with Render.

[riimuru]

Lgtm