Add Helix editor to bash autocompletion (#3137)

shell/completion.bash

@@ -310,7 +310,7 @@ complete -o default -F _fzf_opts_completion fzf-tmux
 d_cmds="${FZF_COMPLETION_DIR_COMMANDS:-cd pushd rmdir}"
 a_cmds="
   awk cat diff diff3
-  emacs emacsclient ex file ftp g++ gcc gvim head hg java
+  emacs emacsclient ex file ftp g++ gcc gvim head hg hx java
   javac ld less more mvim nvim patch perl python ruby
   sed sftp sort source tail tee uniq vi view vim wc xdg-open
   basename bunzip2 bzip2 chmod chown curl cp dirname du