Allow ctrl-r ctrl-a ctrl-e.

Add 3 functions for vim.
ctrl-r for backward search.
ctrl-a to the beginning of line
ctrl-e to the end of line.

plugins/vi-mode/vi-mode.plugin.zsh

@@ -28,6 +28,12 @@ bindkey '^?' backward-delete-char
 bindkey '^h' backward-delete-char
 bindkey '^w' backward-kill-word
 
+# allow ctrl-r to perform backward search in history
+bindkey '^r' history-incremental-search-backward
+# allow ctrl-a and ctrl-e to move to beginning/end of line
+bindkey '^a' beginning-of-line
+bindkey '^e' end-of-line
+
 # if mode indicator wasn't setup by theme, define default
 if [[ "$MODE_INDICATOR" == "" ]]; then
   MODE_INDICATOR="%{$fg_bold[red]%}<%{$fg[red]%}<<%{$reset_color%}"