gitconfig: Add autocorrect and other things

* Add autocorrect to fix typos.
* Turn on other helpers.
Merge remote-tracking branch 'github/master'
env: Move exports to shell_env.sh

* Move bash_env.sh to shell_env.sh
* Motivation is to share this with zsh.
shell_env: Add support for tmux

* If shells had a simple built-in I can use for both.
* Not willing to shell out to call a binary.
zsh: Initial zshrc file

* Initial zshrc file.