vimrc: Ctrl-P should ignore dot directories.
vimrc: Ctrl+S to save in normal mode. Saves two strokes.
vimrc: Add normal mode mapping for markdown files.

When writing, I like to markup anchors that I'm going to use as I
write, but without the reference link. After I'm done, I go back and
add them. This is an easy way to find them.
gitconfig: Add public GPG signing key.