Quick improvement: Better instructions to change the Community URL

Improve the description by adding the Permalinks hint:

Change Community URL

We don't recommend to change URL of your portal if you already have lots of contents. All of the portal related URLs will be changed by your new URL.

Step 1:
https://example.com/ Enter your new slug

Step 2: Re-save your Permalinks

Click the link, sroll down, click the Save button
https://example.com/wp-admin/options-permalink.php

Step 3: Check your new Community URL: https://example.com/newslug