Update customer feature proposal workflow

Why is this change being made?

Customer requirements, priorities, and desired results can be difficult for Support to assess and communicate in feature request issues.

GitLab provides customers (and users) with a direct path to raise problems, voice concerns, make feature requests, or communicate impact and priority of issues.

GitLab has "everyone can contribute" as our company mission.

Closes gitlab-com/support/support-team-meta#2141 (closed)

Does this MR meet the acceptance criteria?

Work in progress!

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what