Regular Expression Threat Protection documentation has to Updated

[AnuGayan]

Description:
Regular Expression Threat Protection documentation had to be updated with UI changes in APIM 4.3.0,

Current doc

New Steps,

1. Create an API or edit an existing API.
2. Go to Policies under the API Configuration sub-section from the left hand panel
3. As required, drag and drop the Regex Policy from the Policy List tab into Request Flow.
4. Scroll down and Save the changes.