update readme to indicate bzlmod is now supported (#172)

README.md

@@ -122,7 +122,6 @@ Steps to get up and running:
 
 ## Known Issues
 
-- Loading external dependencies when `bzlmod` is enabled does not yet work correctly (coming soon, tracking in https://github.com/withered-magic/starpls/issues/168).
 - Type guards are not supported.
 - Type checker shows some false positives, especially when the definitions from the builtins proto are incorrect.
 - When `--enable-bzlmod` is set, type checking/goto definition may be slow for a given file the first time it is loaded. This is because resolution of repo mappings, done with `bazel mod dump_repo_mappings`, is done lazily.