Move async initialization into start function to keep in one place

src/async.zsh

@@ -64,5 +64,3 @@ _zsh_autosuggest_async_recreate_pty() {
 	# Set up input handler from the pty
 	zle -F $_ZSH_AUTOSUGGEST_PTY_FD _zsh_autosuggest_async_suggestion_ready
 }
-
-add-zsh-hook precmd _zsh_autosuggest_async_recreate_pty

src/start.zsh

@@ -10,6 +10,9 @@ _zsh_autosuggest_start() {
 	_zsh_autosuggest_feature_detect
 	_zsh_autosuggest_check_deprecated_config
 	_zsh_autosuggest_bind_widgets
+
+	_zsh_autosuggest_async_recreate_pty
+	add-zsh-hook precmd _zsh_autosuggest_async_recreate_pty
 }
 
 add-zsh-hook precmd _zsh_autosuggest_start