fixing GaussDB titles

metadata.yaml

@@ -966,8 +966,7 @@ categories:
         - name: docs-database-rw
           permission: write
       repository: docs/data-replication-service
-    - service_title: GaussDB Enterprise-class Distributed Database compatible with
-        MySQL
+    - service_title: GaussDB (for MySQL)
       service_type: gaussdb_mysql
       docs:
         - html_location: docs/gaussdb_mysql/api-ref
@@ -986,7 +985,7 @@ categories:
         - name: docs-database-rw
           permission: write
       repository: docs/gaussdb-mysql
-    - service_title: GaussDB Distributed Multi-model NoSQL Database
+    - service_title: GaussDB NoSQL
       service_type: gaussdb_nosql
       docs:
         - html_location: docs/gaussdb_nosql/umn
@@ -999,8 +998,7 @@ categories:
         - name: docs-database-rw
           permission: write
       repository: docs/gaussdb-nosql
-    - service_title: GaussDB Enterprise-grade Relational Database on the openGauss
-        ecosystem
+    - service_title: GaussDB (openGauss)
       service_type: opengauss
       docs:
         - html_location: docs/opengauss/api-ref