Add PR Builder guide to docs

docs/guides/autobuild-docs-for-pull-requests.rst

@@ -0,0 +1,52 @@
+Autobuild Documentation for Pull Requests
+=========================================
+
+Read the Docs allows autobuilding documentation for pull/merge requests for GitHub or GitLab projects.
+This feature is currently available under a :doc:`Feature Flag </guides/feature-flags>`.
+So, you can enable this feature by sending us an `email <mailto:support@readthedocs.org>`__ including your project URL.
+
+Features
+========
+
+- **Build on Pull/Merge Request Event:** We create an external version and trigger a build for that version
+  when we receive pull/merge request open event from the webhook.
+  We also trigger a new build when a new commit has been pushed to the Pull/Merge Request.
+
+- **Warning Banner for Pull/Merge Request Documentation:** While building documentation for pull/merge requests
+  we add a warning banner at the top of those documentations to let the users know that
+  this documentation was generated from pull/merge requests and is not the main documentation for the project.
+
+- **Send Build Status Notification:** We send build status reports to the status API of the provider (e.g. GitHub, GitLab).
+  When a build is triggered for a pull/merge request we send build pending notification with the build URL
+  and after the build has finished we send success notification if the build succeeded without any error
+  or failure notification if the build failed.
+
+.. figure:: ../_static/images/guides/github-build-status-reporting.gif
+    :align: center
+    :alt: GitHub Build Status Reporting for Pull Requests.
+    :figwidth: 80%
+    :target: ../_static/images/guides/github-build-status-reporting.gif
+
+    GitHub Build Status Reporting for Pull Requests
+
+Troubleshooting
+===============
+
+After the feature is enabled on your project if everything does not work as expected,
+some common causes might be:
+
+#. Project repository should be from GitHub or GitLab. This feature is only available for GitHub or GitLab.
+
+#. Social Account (GitHub, Gitlab) is not connected with Read the Docs account.
+   If your project repository provider is GitHub or GitLab you need to make sure
+   that you Read the Docs account is connected with that providers social account.
+   You can check this by going to your `profile settings`_.
+
+#. Webhook is not properly setup. You need to make sure your webhook is properly setup
+   to handle events. You can setup or ``re-sync`` the webhook from you projects admin dashboard.
+   Learn more about setting up webhooks from our :doc:`Webhook Documentation </webhooks>`.
+
+If you have tried all the above troubleshooting and still getting issues,
+please let us know by sending us an `email <mailto:support@readthedocs.org>`__.
+
+.. _profile settings: https://readthedocs.org/accounts/social/connections/

docs/guides/index.rst

@@ -32,6 +32,7 @@ These guides will help you customize or tune aspects of the Read the Docs build
 .. toctree::
     :maxdepth: 1
 
+    autobuild-docs-for-pull-requests
     build-notifications
     build-using-too-many-resources
     technical-docs-seo-guide