Adjusted the list of mock modules for the platform API documentation build. This…

Adjusted the list of mock modules for the platform API documentation build. This prevents build failures when Sphinx cannot import modules. Addresses https://openedx.atlassian.net/browse/DOC-2638.

docs/en_us/platform_api/source/conf.py

@@ -143,6 +143,14 @@ MOCK_MODULES = [
     'rest_framework_oauth.authentication',
     'certificates.api',
     'courseware.date_summary',
+    'rest_framework_jwt',
+    'rest_framework_jwt.authentication',
+    'microsite_configuration',
+    'xmodule.assetstore',
+    'xmodule.assetstore.assetmgr',
+    'xmodule.assetstore.assetmgr.AssetManager',
+    'xmodule.contentstore.django',
+    'piexif',
 ]
 
 for mod_name in MOCK_MODULES: