Workbook - AppGw WAF Triage Workbook - support Microsoft Default Ruleset 2.1

**Is your feature request related to a problem? Please describe.**
I'm looking for update workbook - [AppGw WAF Triage Workbook](https://github.com/Azure/Azure-Network-Security/tree/master/Azure%20WAF/Workbook%20-%20AppGw%20WAF%20Triage%20Workbook) to support Microsoft Default Ruleset 2.1. For example rule description rules don't work.

**Describe the solution you'd like**
I would like to have valid urls to rule descriptions for DRS 2.1 as it is for OWASP 3.2.

**Describe alternatives you have considered**
Just rollback to OWASP 3.2