:octocat: Don't scan .git folder by default ⚡

[benedikt-bartscher]

just a minimalist issue to improve performance.
currently yamlfixer scans the whole .git folder for yaml files by default. it can be observed by using yamlfixers -d flag

[adriens]

@tamere-allo-peter looks like we have a Quicfkix here 💭

[tamere-allo-peter]

Looks like à duplicate of #189 : yamlfixer should simply ignore the very same files that are ignored by yamllint, which it currently does not, but should ignore files on its own : ignoring .git would be introducing a special case for no reason.