Added release notes for Djblets 1.0.11.
Review Request #10449 — Created March 18, 2019 and submitted — Latest diff uploaded
This covers the new work on an embeddable integrations configuration UI,
the new CSS rules for config forms, the fallback avatar service, and the
upgrade to Less 3.9.
Checked for spelling errors.
Built the docs. Checked for build errors and bad links.