Add related docs menu item

Adding a section to the SSSOM docs for related documentation, such as SSSOM Toolkit and SSSOM Java.

mkdocs.yml

@@ -52,6 +52,13 @@ nav:
     - Matching tool implementation guide: matching-tool-implementation-guide.md
     - SSSOM profiles: sssom-profiles.md
     - Glossary: glossary.md
+  - Related documentation:
+    - SSSOM Toolkit: "https://mapping-commons.github.io/sssom-py/index.html#"
+    - SSSOM Java: "https://incenp.org/dvlpt/sssom-java/"
+    - Semantic Mapping Vocabulary (SEMAPV): "https://mapping-commons.github.io/semantic-mapping-vocabulary/"
+    - LinkML: "https://linkml.io/linkml/"
+    - OBO Academy: "https://oboacademy.github.io/obook/"
+    - Monarch Initiative: "https://monarch-initiative.github.io/monarch-documentation/"
 
 site_url: https://mapping-commons.github.io/sssom/
 repo_url: https://github.com/mapping-commons/sssom/