[zsh] Fix #404 - Escape $ in $LBUFFER

shell/key-bindings.zsh

@@ -38,7 +38,7 @@ bindkey '\ec' fzf-cd-widget
 # CTRL-R - Paste the selected command from history into the command line
 fzf-history-widget() {
   local selected num
-  selected=( $(fc -l 1 | $(__fzfcmd) +s --tac +m -n2..,.. --tiebreak=index --toggle-sort=ctrl-r -q "$LBUFFER") )
+  selected=( $(fc -l 1 | $(__fzfcmd) +s --tac +m -n2..,.. --tiebreak=index --toggle-sort=ctrl-r -q "${LBUFFER//$/\\$}") )
   if [ -n "$selected" ]; then
     num=$selected[1]
     if [ -n "$num" ]; then