Workflow Trigger documentation doesn't include GitLab even though it's supported

Issue Summary

Our documentation on Configuring workflow triggers doesn't mention GitLab as supported DVCS provider. However, it works.

This is reproducible on Data Center: yes

Steps to Reproduce

1. Add GitLab as a DVCS provider
2. Create a workflow trigger based on GitLab
   GitLab logo would be identified as GitHub (JSWSERVER-21787)

Expected Results

Our Documentation should mention GitLab as supported provider as well

Actual Results

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available