docs(usage): Clarify GitVersion.Core as the library API

Author: arturcic

docs/input/docs/usage/library.md

@@ -15,9 +15,9 @@ patch releases, it's a useful option to some.
 
 :::{.alert .alert-warning}
 **Warning**
-The library API is not stable and does not follow the semantic versioning
+The library API (GitVersion.Core) is not stable and does not follow the semantic versioning
 of the GitVersion tool. A patch release of the tool may break the library
 and we will refactor and change the library API without notice.
 :::
 
-<a href="/api" class="btn btn-primary">Explore the GitVersion library API</a>
+<a href="/api" class="btn btn-primary">Explore the GitVersion Core library API</a>