Update CHANGELOG.md

updated readthedocs for making controlling_em mandatory #1447

Author: kkarthik11

CHANGELOG.md

@@ -16,7 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix transformer susceptance in readTheDocs to negative values [#1078](https://github.com/ie3-institute/PowerSystemDataModel/issues/1078)
 - Added mising fields to field validation [#1422](https://github.com/ie3-institute/PowerSystemDataModel/issues/1422)
 - Fixed the issues with rtd for Cylindrical thermal storage [#1273](https://github.com/ie3-institute/PowerSystemDataModel/issues/1273)
-- - Updated Controlling_em for all the loads in readthedocs[#1447](https://github.com/ie3-institute/PowerSystemDataModel/issues/1447)
+- Updated Controlling_em for all the loads in readthedocs[#1447](https://github.com/ie3-institute/PowerSystemDataModel/issues/1447)
 
 ### Changed
 - Updated CI-Pipeline to run task `Deploy` and `Staging` only for `Main` [#1403](https://github.com/ie3-institute/PowerSystemDataModel/issues/1403)