base: Allow loading more specific 'run-help' function

Allow loading more specific 'run-help' function from $fpath. This
allows automatically looking up specific sub-command helper if
available instead of the static default ('man').

See: ccc9cff9e2/Functions/Misc/run-help (L3-L8)

init.zsh

@@ -182,6 +182,9 @@ zstyle -a ':prezto:load' zmodule 'zmodules'
 for zmodule ("$zmodules[@]") zmodload "zsh/${(z)zmodule}"
 unset zmodule{s,}
 
+# Load more specific 'run-help' function from $fpath.
+unalias run-help && autoload -Uz run-help
+
 # Autoload Zsh functions.
 zstyle -a ':prezto:load' zfunction 'zfunctions'
 for zfunction ("$zfunctions[@]") autoload -Uz "$zfunction"