Update CHANGELOG.md

Author: appilon

CHANGELOG.md

@@ -9,6 +9,7 @@ ENHANCEMENTS:
 
  - Report progress for validate command ([#336](https://github.com/hashicorp/terraform-ls/pull/336))
  - Report deprecated completion items as such ([#337](https://github.com/hashicorp/terraform-ls/pull/337))
+ - Preloaded schemas now includes official+partner providers. A change in the implementation now means only HashiCorp releases will include the preloaded schemas. Manual builds or `go get` will compile and run correctly however users in uninitalized projects will not receive resource completion with such builds. ([#341](https://github.com/hashicorp/terraform-ls/pull/341))
 
 INTERNAL: