[README] create template file if it doesn't exist

README.md

@@ -52,6 +52,7 @@ by following the instructions below:
   setopt EXTENDED_GLOB
   for template_file ( ${ZDOTDIR:-${HOME}}/.zim/templates/* ); do
     user_file="${ZDOTDIR:-${HOME}}/.${template_file:t}"
+    touch ${user_file}
     ( print -n "$(<${template_file})\n$(<${user_file})" >! ${user_file} ) 2>/dev/null
   done
   ```