feat: Added bitbucket icon

[bdbch]

Added bitbucket icon as requested in #479

Preview:

[codecov]

Codecov Report

Merging #484 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master   #484   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           5      5           
  Lines          34     34           
  Branches        3      3           
=====================================
  Hits           34     34

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[mittalyashu]

I don't know, if it aligns with BitBucket brand guidelines, we need to ask their design team for the same.

[mittalyashu]

Icon	Suggestion

@locness3, what do you think?

[locness3]

idk

[colebemis]

Thanks for opening this PR, @bdbch! But I'm going to close this because we've decided to stop adding logo icons to Feather (see #763 for more details).