docs: Add roadmap section to README
Description
As part of the work in gitlab-org/editor-extensions/meta#21 (closed) to standardize the content of the groupeditor extensions projects, add a Roadmap
subheading to the README.
Related Issues
Related to Set up a common skeleton for extension docs (gitlab-org/editor-extensions/meta#21 - closed)
Resolves #[issue_number]
How has this been tested?
Screenshots (if appropriate)
Types of changes
-
Bug fix (non-breaking change which fixes an issue) -
New feature (non-breaking change which adds functionality) -
Breaking change (fix or feature that would cause existing functionality to change) -
Documentation -
Chore (Related to CI or Packaging to platforms) -
Test gap