docs: Added an example for promptChoice

Author: N3WK1D

assets/chezmoi.io/docs/reference/templates/init-functions/promptChoice.md

@@ -1,3 +1,12 @@
 # `promptChoice` *prompt* *choices* [*default*]
 
 `promptChoice` prompts the user with *prompt* and *choices* and returns the user's response. *choices* must be a list of strings. If *default* is passed and the user's response is empty then it returns *default*.
+
+!!! example
+
+    ```
+    {{- $choices := list "desktop" "server" -}}
+    {{- $hosttype := promptChoice "What type of host are you on" $choices -}}
+    [data]
+        hosttype = {{- $hosttype | quote -}}
+    ```