Reorder/restyle "description template" link in MR form

Issue

From user journey:

It was surprising that "description templates" opened the docs in a new tab when the link just above it was a button that added "Draft" to the title. The button/link are styled the same, but behave very differently.

Proposal

Make it clearer that adding description templates leads to the docs.

Clarify that the link is about setting up description templates for the project, not adding one to your current MR.