chore(docs): add vertexai docs (#11713)

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Author: ncybul

docs/integrations.rst

@@ -478,6 +478,13 @@ urllib3
 .. automodule:: ddtrace.contrib.urllib3
 
 
+.. _vertexai:
+
+vertexai
+^^^^^^^^^^^^^^^^^^^
+.. automodule:: ddtrace.contrib.vertexai
+
+
 .. _vertica:
 
 Vertica

docs/spelling_wordlist.txt

@@ -266,6 +266,7 @@ username
 uvicorn
 vendored
 versioned
+vertexai
 vertica
 w3c
 websocket