feat(github-invite): missing member detection docs (#7926)

Author: cathteng

src/docs/product/integrations/source-code-mgmt/github/github-missing-members-banner.png

@@ -264,6 +264,22 @@ This feature will be automatically enabled for you once your GitHub integration
 
 ![How to disable Sentry comments on GitHub pull requests](github-org-settings.png)
 
+### Missing Member Detection
+
+If there are users committing to Github repositories linked to Sentry and they're not members of your organization, Sentry detects them as missing members. Once a month, Sentry sends organization owners and managers an email reminding them to invite those users to join their org. Sentry also shows a banner to invite missing members in the **Settings > Members** page.
+
+![Github missing members invite banner](github-missing-members-banner.png)
+
+The banner shows the 5 most active contributors that are not yet in the organization. To see all missing members (up to 50), click "View All" in the banner. To snooze the banner, click the ellipsis, then select "Hide Missing Members".
+
+Clicking "View All" on the invite banner will display the invite modal. From here, you can select multiple users and assign roles and teams before inviting them.
+
+![Github missing members invite modal](github-missing-members-modal.png)
+
+By default, this feature is automatically enabled once your GitHub integration has been set up. To disable it, go to **Settings > Integrations > GitHub** and toggle it off.
+
+![How to disable missing member detection](github-org-settings.png)
+
 ### Stack Trace Linking
 
 <Note>