fix: do not apply editorconfig to git commit msg

The `max_line_length` property was set to 100 for all filetypes, which
led to git commit messages being wrapped at 100 characters instead of
the usual 75. This introduces an exception for the special file used by
git to write commit messages.

Signed-off-by: Prajwal S N <[email protected]>

Author: snprajwal

.editorconfig

@@ -15,3 +15,6 @@ indent_size = 2
 
 [*.{yml,yaml}]
 indent_size = 2
+
+[COMMIT_EDITMSG]
+max_line_length = unset