Add `~/bin` to shell path

For some reason, I thought that this was a default provided by bash/zsh.
Turns out it is not be the case.

shell/env

@@ -3,7 +3,7 @@ export EDITOR='vim'
 export PAGER='less'
 
 # Paths
-export PATH=$HOME/dotfiles/bin:$PATH
+export PATH=$HOME/dotfiles/bin:$HOME/bin:$PATH
 export MANPATH=$MANPATH:$HOME/dotfiles/shell/man
 
 # Config Files: Which Are Sourced, And When?