Fix dead link to "CI services" Jekyll (mmistakes#2692)

* Fix mmistakes#2635

* Update CHANGELOG and history

CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+
+### Bug Fixes
+
+- Fix dead link to CI services in documentation. [#2635](https://github.com/mmistakes/minimal-mistakes/issues/2635) [#2692](https://github.com/mmistakes/minimal-mistakes/pull/2692)
+
 ## [4.20.2](https://github.com/mmistakes/minimal-mistakes/releases/tag/4.20.2)
 
 ### Bug Fixes

docs/_docs/01-quick-start-guide.md

@@ -105,7 +105,7 @@ To do so fork the [Minimal Mistakes theme](https://github.com/mmistakes/minimal-
 
 [netlify-jekyll]: https://www.netlify.com/blog/2015/10/28/a-step-by-step-guide-jekyll-3.0-on-netlify/
 [gitlab-jekyll]: https://about.gitlab.com/2016/04/07/gitlab-pages-setup/
-[ci-jekyll]: https://jekyllrb.com/docs/continuous-integration/
+[ci-jekyll]: https://jekyllrb.com/docs/deployment/automated/#continuous-integration-service
 
 ### Remove the Unnecessary
 

docs/_docs/18-history.md

@@ -9,9 +9,15 @@ last_modified_at: 2020-09-07T10:03:41-04:00
 toc: false
 ---
 
+## Unreleased
+
+### Bug Fixes
+
+- Fix dead link to CI services in documentation. [#2635](https://github.com/mmistakes/minimal-mistakes/issues/2635) [#2692](https://github.com/mmistakes/minimal-mistakes/pull/2692)
+
 ## [4.20.2](https://github.com/mmistakes/minimal-mistakes/releases/tag/4.20.2)
 
-## Bug Fixes
+### Bug Fixes
 
 - Fix broken link in documentation. [#2677](https://github.com/mmistakes/minimal-mistakes/issues/2677)
 - Fix typo in documentation. [#2678](https://github.com/mmistakes/minimal-mistakes/issues/2678)