Manually update READMEs, quickstart, and top-level stuff

Author: scotthart

CHANGELOG.md

@@ -9,16 +9,26 @@ for details on updating existing applications using v1.x.y or v2.x.y.
 
 ## v3.4.0 - TBD
 
+### [Data Catalog](/google/cloud/datacatalog/README.md)
+
+- Added Data Lineage Config Management library.
+
+### [Dataplex](/google/cloud/dataplex/README.md)
+
+- Added Business Glossary library.
+- Added CMEK library.
+- Added Data Products library.
+
 ## v3.3.0 - 2026-03
 
 ### New Libraries
 
 We are happy to announce the following GA libraries. Unless specifically noted,
 the APIs in these libraries are stable, and are ready for production use.
 
-- [Gemini Enterprise for Customer Experience API](google/cloud/ces/README.md)
-- [Cluster Director API](google/cloud/hypercomputecluster/README.md)
-- [Vector Search API](google/cloud/vectorsearch/README.md)
+- [Gemini Enterprise for Customer Experience API](/google/cloud/ces/README.md)
+- [Cluster Director API](/google/cloud/hypercomputecluster/README.md)
+- [Vector Search API](/google/cloud/vectorsearch/README.md)
 - [Vision AI API](/google/cloud/visionai/README.md)
 - [Workload Manager](/google/cloud/workloadmanager/README.md)