Add some content to Post-0Repo Creation Checklist

Signed-off-by: Andrei Jiroh Eugenio Halili <andreijiroh@madebythepins.tk>

Author: Andrei Jiroh Eugenio Halili

src/docs/maintainer-docs/example-mergify-config.mdx

@@ -0,0 +1,34 @@
+---
+title: Example Mergify configurations
+---
+
+## Automagically merge Dependabot PRs
+
+```yml
+# Conflicts with the following PR rules, please comment them out first:
+# - Automate base image upgrade review process from Dependabot
+# - Ship Dependabot PRs when approved by humans
+# Remember that you MUST ALWAYS REVIEW THE CHANGELOGS
+# before your release it as https://github.io/cdr/code-server/releases.
+  - name: Automagically ship Dependabot PRs
+    conditions:
+      - author~=^dependabot(|-preview)\[bot\]$
+      - label=Updated by Dependabot
+      - label=packages/docker-base-images
+      - base=main
+    actions:
+      review:
+        type: APPROVE
+        message: |
+           Approving and merging @dependabot's pull request, to be shipped in the following image tags: `develop`
+
+           Maintainers have been advised to to create an new release regarding this base image upgrade as soon as possible for patches, including security fixes, and within the next 48-72 hours for minor releases. For major releases, expect breaking changes and notify your users accordingly before creating an new GitHub release.
+
+           To learn more about this guideline, please read your `docs/release-management/automated-base-image-upgrades.md` or through <https://cdrs-docs.rtapp.tk/base-images-dependabot> in case your copy of maintainers' docs go outdated.
+
+           --
+
+           This PR has been merged automagically by Mergify. Read `docs/post-repo-creation/mergify.md` or visit <https://cdrs-docs.rtapp.tk/mergify> to learn more.
+      merge:
+        action: merge
+```

src/docs/maintainer-docs/post-repo-creation-checklist.mdx

@@ -1,3 +1,19 @@
 ---
 title: Post Repository Creation Checklist
----
+---
+
+After you either generated a new repo from an GitHub template or duplicated it, you need to configure encrypted secrets for GitHub Actions, update contact links, and install Mergify, among other things.
+
+## TL;DR
+
+Here's the gist of what you do as a new template maintainer:
+
+* [Install Mergify on your account/org](https://github.com/apps/mergify/installations/new). We're working on an GitHub Action workflow if you don't prefer to use Mergify instead.
+* Configure encrypted secrets for Docker Hub, RHQCR (the public instance on <https://quay.io>) and GHCR
+* Adjust GitHub repository settings, and optionally update sponsor links.
+
+## Step 1: Installing Mergify
+
+**Transferring to or has repo creation permissions in `code-server-boilerplates` org?** Skip this step, since we installed that GitHub app across the org.
+
+Otherwise, [install the app](https://github.com/apps/mergify/installations/new) in an account/org where your template is. If you don't want to install the app across all repos, select **Only select repositories** and manually add that repo before hitting `Install`.