add tags.yaml instructions

Signed-off-by: Riaan Kleinhans <[email protected]>

Author: riaankleinhans

README.md

@@ -106,3 +106,8 @@ The current Technical Advisory Groups will be spun down during 2025 and replaced
 * [Contributor Strategy SubProject and Advocacy](./toc_subprojects/contributor-strategy-subproject-and-advocacy/)
 * [Mentoring SubProject](./toc_subprojects/mentoring-subproject/)
 * [Project Reviews SubProject](./toc_subprojects/project-reviews-subproject/)
+
+
+### Updating TAG or SubProject README files
+
+To modify the README files for individual TAGs or subprojects, please **do not edit them directly**. Instead, the source of truth for these files is the [`tags.yaml`](https://github.com/cncf/toc/blob/main/tags.yaml) file. To understand the process for updating these READMEs by modifying `tags.yaml`, please refer to the [Updating TOC TAG and Subproject README Files document](./generator/updating-tag-and-toc=subproject-readme-files.md).

generator/updating-tag-and-toc=subproject-readme-files.md

@@ -0,0 +1,39 @@
+# Updating TOC TAG and Subproject README Files
+
+This document outlines the process for updating the README files located in the [tags](https://github.com/cncf/toc/tree/main/tags) and [toc_subprojects](https://github.com/cncf/toc/tree/main/toc_subprojects) directories. These README files are automatically generated and updated based on the content of the [`tags.yaml`](https://github.com/cncf/toc/blob/main/tags.yaml) file.
+
+**The Single Source of Truth: `tags.yaml`**
+
+The `tags.yaml` file serves as the central source of information for generating and updating the README files for both TAGs and subprojects. To modify the content of these READMEs, you **must** update the `tags.yaml` file directly.
+
+**Who can Update:**
+
+Anyone can create a pull request in the `cncf/toc` repository, only TOC members can review and merge changes to the `tags.yaml` file.
+
+**How to Update:**
+
+1.  **Locate the `tags.yaml` file:** This file is located at the root of the `cncf/toc` repository: [https://github.com/cncf/toc/blob/main/tags.yaml](https://github.com/cncf/toc/blob/main/tags.yaml).
+
+2.  **Make your changes:** Carefully edit the `tags.yaml` file to reflect the desired updates for the TAG or subproject README files. Ensure the YAML syntax is correct.
+
+3.  **Create a Pull Request (PR):**
+    * **Important:** A PR that aims to update the TAG and subproject README files **must only contain changes to the `tags.yaml` file.** Any other changes in the PR will not trigger the automatic README updates.
+
+**Automation in Action:**
+
+The `github-project-automation` and `cncf-automation-bot` handle the automatic updates of the README files based on your changes to `tags.yaml`:
+
+* **Updates from a Branch within the `cncf/toc` Repository:**
+    * When you create a PR from a branch within the `cncf/toc` repository that modifies only the `tags.yaml` file, the `github-project-automation` will automatically:
+        * Generate the necessary updates to the relevant README files in the `tags` and `toc_subprojects` directories.
+        * Push these updated README files as an **additional commit** to your existing PR.
+
+* **Updates from a Fork of the `cncf/toc` Repository:**
+    * If you create a PR from a fork of the `cncf/toc` repository that modifies only the `tags.yaml` file, the `cncf-automation-bot` will:
+        * Create a **new PR** on the `cncf/toc` repository.
+        * This new PR will contain both your changes to the `tags.yaml` file and the automatically generated updates to the relevant README files.
+        * The `cncf-automation-bot` will automatically close the original PR from your fork and add comments to both the original and the new PR to link them.
+
+**Key Takeaway:**
+
+To update the README files in the `tags` and `toc_subprojects` directories, your PR **must only include modifications to the `tags.yaml` file**. The automation will then take care of generating and updating the corresponding README files.