update CHANGELOG for version 5.2.0a0

Author: joshuadavidthomas

CHANGELOG.md

@@ -18,6 +18,8 @@ and this project attempts to adhere to [Semantic Versioning](https://semver.org/
 
 ## [Unreleased]
 
+## [5.2.0a0]
+
 ### Added
 
 - Added `html-django` as an alternative Language ID for Django templates
@@ -72,7 +74,9 @@ and this project attempts to adhere to [Semantic Versioning](https://semver.org/
 
 - Josh Thomas <[email protected]> (maintainer)
 
-[unreleased]: https://github.com/joshuadavidthomas/django-language-server/compare/v5.1.0a2...HEAD
+[unreleased]: https://github.com/joshuadavidthomas/django-language-server/compare/v5.2.0a0...HEAD
 [5.1.0a0]: https://github.com/joshuadavidthomas/django-language-server/releases/tag/v5.1.0a0
 [5.1.0a1]: https://github.com/joshuadavidthomas/django-language-server/releases/tag/v5.1.0a1
 [5.1.0a2]: https://github.com/joshuadavidthomas/django-language-server/releases/tag/v5.1.0a2
+
+[5.2.0a0]: https://github.com/joshuadavidthomas/django-language-server/releases/tag/v5.2.0a0