[zsh] Move vi init to init_env_vi; set EDITOR in that function

zsh/func/init_env

@@ -3,7 +3,6 @@
 
 export PAGER="less"
 export MANPAGER=$PAGER
-export EDITOR="vim"
 export VISUAL=$EDITOR
 export LESSHISTFILE="-"
 export GREP_OPTIONS="--color=auto"

zsh/func/init_env_vi

@@ -5,6 +5,10 @@
 
 if whence -cp nvim &> -; then
     alias vi=nvim
+    export EDITOR=nvim
 elif whence -cp vim &> -; then
     alias vi=vim
+    export EDITOR=vim
 fi
+
+export editor=vi