Improve suggested configuration in README

[notpeter]

• Add matcher for .git/config
• Remove *.gitconfig (already matched by the language config:

git_firefly/languages/gitconfig/config.toml

Lines 3 to 9 in c598e3c

	path_suffixes = [
	# https://github.com/neovim/neovim/blob/master/runtime/lua/vim/filetype.lua
	"config.worktree",
	".gitconfig",
	".gitmodules",
	".lfsconfig",
	]

[MrSubidubi]

Thanks!

[injust]

@notpeter I think you didn't actually remove *.gitconfig?

EDIT: Actually, what's in path_suffixes seems to only match a file named exactly .gitconfig, but not foo.gitconfig. So never mind -- what was merged is correct.