Merge pull request #432 from noqdev/docs/iambic-gist-repo

Add docs for the IAMbic Gist repo

docs/web/docs/1-getting_started/7-github.mdx

@@ -139,6 +139,13 @@ This page will walk you through the steps of configuring IAMbic, GitHub, and AWS
 7. The IAMbic GitHub action will apply the changes in the PR.
 8. Once git-apply is successful, the GitHub action will close the pull request.
 
+:::tip
+
+If you'd like to use IAMbic in multiple AWS partitions (For example, AWS GovCloud, AWS China, and AWS Commercial),
+you will need to create a separate IAMbic repository and GitHub App for each partition.
+
+:::
+
 ## Setting up GitHub and AWS to work with IAMbic
 
 ### Prerequisites
@@ -169,7 +176,7 @@ permissions from your cloud provider(s).
 	1. Enable "Require status checks to pass before merging". <!-- #TODO Is there a reason the prior 3 settings were on one line and this was on it's own line?  -->
 
 
-# GitHub App integration
+## GitHub App integration
 
 By installing IAMbic GitHub App, the app can integrate the pull-request and merge flow in your iambic templates repository.
 
@@ -191,6 +198,28 @@ By installing IAMbic GitHub App, the app can integrate the pull-request and merg
 12. Click "Generate a private key".
 13. The private key should be downloaded automatically.
 
+
+## Create an Additional GitHub Repository for IAMbic Plan and Apply Summaries
+
+The IAMbic GitHub Application generates Plan and Apply Summaries for each pull request in your IAMbic templates repository.
+These summaries provide an overview of the changes proposed by a pull request, and the results of applying those changes.
+The IAMbic Github Application stores these summaries in a separate repository to allow for easier tracking and management,
+and as it adds comments in each pull request, it provides a link to the summary in this separate repository.
+
+
+1. **Create a new GitHub repository** in your organization that will host the IAMbic Plan and Apply Summaries.
+   The repository must have the same name as your IAMbic templates repository, with `-gist` appended to the end.
+   For example, if your repoistory name is `iambic-templates`, the new repository must be named `iambic-templates-gist`.
+
+2. **Ensure the IAMbic GitHub App has write access to the new repository.
+   - To set the repository permissions:
+     1. Go to your organization settings (https://github.com/organizations/ExampleOrg/settings/profile).
+     2. Select "GitHub Apps" under "Third-party Access" in the left navigation bar.
+     3. Click "Configure" on "Iambic Integrations".
+     4. Under "Repository access" section,
+        ensure that both your IAMbic Templates repository, and the new repository you created in step 1 are selected.
+     5. Click "Save".
+
 ### Store the following secrets in AWS Secrets Manager in the same AWS account running GitHub App lambda function.
 
 1. Go to AWS Secret Manager, the URL will look like `console.aws.amazon.com/secretsmanager/listsecrets`.
@@ -323,7 +352,6 @@ involve pushing changes back to the default branch without requiring manual appr
 5. In "Search for people, teams or apps", type in `iambic-integrations` to click on the GitHub App we have created.
 6. Click "Save changes".
 
-
 ### Finish setting up your local repo