feat(docs): Add docs check target, plus some extra plugins

earthly/docs/Earthfile

@@ -74,7 +74,7 @@ DEVELOP:
     SAVE ARTIFACT /local AS LOCAL $dest
 
 
-build-test:
+check:
     # Test of building docs.
     # Run with `earthly -P +build-test`
     ARG dest=./site

earthly/docs/Readme.md

@@ -2,10 +2,20 @@
 
 This directory contains targets for the Catalyst Documentation builders, and associated UDCs.
 
-## Build
+## Check
 
-To build and save the final artifact locally:
+This target includes a check to ensure the MkDocs base builder works as expected.
 
 ```bash
-earthly --artifact +build/site .
+earthly -P +check
 ```
+
+## Updating Dependencies
+
+If a new dependency is added to `pyproject.toml` ensure to run:
+
+```sh
+poetry lock
+```
+
+in the `earthly/docs` directory to update the locked dependencies.