Ignore files via EditorConfig property #58

Feature description

It should be possible to define inside .editorconfig files, which files should be ignored by ecformat. Maybe with a Boolean property named ecformat_ignore or similar.

Benefits

This would allow ignoring files without a separate ignore file (to use with --ignore-file) as pointed out in this Review comment.

Resources

• Extensions of EditorConfig with custom properties

One performance aspect should be considered for the implementation. Currently, ecformat take a look at the EditorConfig properties for each file. At this point it could check for such a new property ecformat_ignore and skip the file. However, this would imply that it iterates over all files of an ignored directory. This could impact the runtime performance in case of many files in there. Would it be possible to skip such directories without this overhead? How to handle cases that ecformat_ignore is true for a directory, but gets false via an .editorconfig in on of its subdirectories?