Update docs about how CRDs are managed (#1278)

* Update docs about how CRDs are managed

* Address review comments

* Minor refactor in docs

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

docs/install.rst

@@ -45,6 +45,19 @@ This will install the Kanister controller in the ``kanister`` namespace
                                        --namespace kanister
 
 
+Kanister Custom Resource Definitions (CRDs)
+===========================================
+
+Kanister defines a few `Custom Resource Definitions (CRDs) <https://docs.kanister.io/architecture.html#custom-resources>`_
+to express and execute data protection workflows. By default, these CRDs are
+managed (created/updated) by the Kanister controller.
+
+If the Kanister controller doesn't have the permissions to create or
+update CRDs, you can disable that using the ``controller.updateCRDs`` Helm
+flag. If set to ``false``, Helm will manage the CRDs instead of the Kanister
+controller.
+
+
 Building and Deploying from Source
 ==================================