Proposal: Let compinit make standard widgets with _generic instead of _main_complete

[Marlon Richert <marlon.richert@gmail.com>]

How would you feel about changing compinit, so that it rebinds the
standard widgets with `zle -C $_i_line .$_i_line _generic` instead of
`zle -C $_i_line .$_i_line _main_complete`?
(https://github.com/zsh-users/zsh/blob/f4a248f9d38dc02d65610395f4c7f9a95a5d6612/Completion/compinit#L558)

This would make it easier for the end user to define, for example,
different `menu` styles for different widgets. Without using
`_generic`, the end user cannot out-of-the-box define different styles
for different widgets.

Here's the patch:

diff --git Completion/compinit Completion/compinit
index e81cd1604..212bc7cf3 100644
--- Completion/compinit
+++ Completion/compinit
@@ -555,9 +555,9 @@ fi
 for _i_line in complete-word delete-char-or-list expand-or-complete \
   expand-or-complete-prefix list-choices menu-complete \
   menu-expand-or-complete reverse-menu-complete; do
-  zle -C $_i_line .$_i_line _main_complete
+  zle -C $_i_line .$_i_line _generic
 done
-zle -la menu-select && zle -C menu-select .menu-select _main_complete
+zle -la menu-select && zle -C menu-select .menu-select _generic

 # If the default completer set includes _expand, and tab is bound
 # to expand-or-complete, rebind it to complete-word instead.