doc: Add links to novaclient contributor guide

Add links to the document for adding a new microversion support
in python-novaclient.

Depends-On: https://review.opendev.org/667002
Change-Id: Ic58afe401464a0da2b19306e7cc6ce412f177b16

doc/source/contributor/code-review.rst

@@ -234,6 +234,8 @@ If a new microversion API is added, the following needs to happen:
 
 * A new patch for the microversion API change in python-novaclient side
   should be submitted before the microversion change in Nova is merged.
+  See :python-novaclient-doc:`Adding support for a new microversion
+  <contributor/microversions>` in python-novaclient for more details.
 * If the microversion changes the response schema, a new schema and test for
   the microversion must be added to Tempest. The microversion change in Nova
   should not be merged until the Tempest test is submitted and at least

doc/source/contributor/microversions.rst

@@ -368,6 +368,8 @@ necessary to add changes to other places which describe your change:
 
 * Make a new commit to python-novaclient and update corresponding
   files to enable the newly added microversion API.
+  See :python-novaclient-doc:`Adding support for a new microversion
+  <contributor/microversions>` in python-novaclient for more details.
 
 * If the microversion changes the response schema, a new schema and test for
   the microversion must be added to Tempest.