Add a compatibility table to the README

Specifies the versions of the action, CLI and GHES that are jointly compatible.

Author: aeisenberg

CHANGELOG.md

@@ -7,6 +7,7 @@ Note that the only difference between `v2` and `v3` of the CodeQL Action is the
 ## [UNRELEASED]
 
 - Update default CodeQL bundle version to 2.17.2. [#2270](https://github.com/github/codeql-action/pull/2270)
+- Add a compatibility matrix of supported CodeQL Action, CodeQL CLI, and GitHub Enterprise Server versions to the [README.md](README.md). [#2273](https://github.com/github/codeql-action/pull/2273)
 
 ## 3.25.3 - 25 Apr 2024
 
@@ -30,7 +31,7 @@ No user facing changes.
 
   - The `setup-python-dependencies` input to the `init` Action
   - The `CODEQL_ACTION_DISABLE_PYTHON_DEPENDENCY_INSTALLATION` environment variable
-  
+
   We recommend removing any references to these from your workflows. For more information, see the release notes for CodeQL Action v3.23.0 and v2.23.0.
 - Automatically overwrite an existing database if found on the filesystem. [#2229](https://github.com/github/codeql-action/pull/2229)
 - Bump the minimum CodeQL bundle version to 2.12.6. [#2232](https://github.com/github/codeql-action/pull/2232)

CONTRIBUTING.md

@@ -84,6 +84,9 @@ We typically deprecate a version of CodeQL when the GitHub Enterprise Server (GH
 1. Notify users using the old version of CodeQL about the deprecation.
     - Update `CODEQL_NEXT_MINIMUM_VERSION`, `GHES_VERSION_MOST_RECENTLY_DEPRECATED`, and `GHES_MOST_RECENT_DEPRECATION_DATE` in `src/codeql.ts` to reflect the new minimum version of CodeQL and the GHES version that has just been deprecated.
     - Add a changelog note announcing the deprecation.
+    - Update the CLI version references in [README.md](README.md):
+        * Update the badge at the top of the file.
+        * Update the supported versions section by adding a new row to the compatibility table.
     - Example PR: https://github.com/github/codeql-action/pull/1884
 1. Release the Action, or wait for the next scheduled release of the Action, then wait at least a week so users have time to see and act on the deprecation warning.
 1. Remove support for the old version of CodeQL.
@@ -96,6 +99,7 @@ We typically deprecate a version of CodeQL when the GitHub Enterprise Server (GH
     - Do the same for PR checks that aren't auto-generated.
     - Add a changelog note announcing the new minimum version of CodeQL that is now required.
     - Example PR: https://github.com/github/codeql-action/pull/1907
+1. If the version of CodeQL being deprecated is a major or minor version, then mark the corresponding [entry in the README.md](README.md#supported-versions-of-the-codeql-cli-and-github-enterprise-server) as deprecated as well (change `No` to `Yes`).
 
 ## Deprecating a CodeQL Action version (write access required)
 

README.md

@@ -1,3 +1,6 @@
+
+![Supports CodeQL CLI v2.12.6 - v2.17](https://img.shields.io/badge/Supports_CodeQL_CLI-v2.12.6_--_v2.17-blue)
+
 # CodeQL Action
 
 This action runs GitHub's industry-leading semantic code analysis engine, [CodeQL](https://codeql.github.com/), against a repository's source code to find security vulnerabilities. It then automatically uploads the results to GitHub so they can be displayed on pull requests and in the repository's security tab. CodeQL runs an extensible set of [queries](https://github.com/github/codeql), which have been developed by the community and the [GitHub Security Lab](https://securitylab.github.com/) to find common vulnerabilities in your code.
@@ -33,6 +36,19 @@ To provide the best experience to customers using older versions of GitHub Enter
 
 For more information, see "[Code scanning: deprecation of CodeQL Action v2](https://github.blog/changelog/2024-01-12-code-scanning-deprecation-of-codeql-action-v2/)."
 
+## Supported versions of the CodeQL CLI and GitHub Enterprise Server
+
+We typically release new minor versions of the CodeQL Action and CLI when a new minor version of GitHub Enterprise Server (GHES) is released. When a version of GHES is deprecated, the corresponding CodeQL Aciton and CLI releases are deprecated as well.
+
+| CodeQL Action Versions | CodeQL CLI Versions | GHES Versions | Deprecated? |
+|----------------|------------|-----|--|
+| `v3.25`, `v2.25` | ![Supports CodeQL CLI v2.12.6 - v2.17](https://img.shields.io/badge/Supports_CodeQL_CLI-v2.12.6_--_v2.17-blue) | `v3.9` - `v3.12` | No |
+| `v3.23`, `v2.23`, `v3.24`, `v2.24` | ![Supports CodeQL CLI v2.11.6 - v2.16](https://img.shields.io/badge/Supports_CodeQL_CLI-v2.11.6_--_v2.16-blue) | `v3.8` - `v3.11` | No |
+| `v3.22`, `v2.22` | ![Supports CodeQL CLI v2.10.5 - v2.15](https://img.shields.io/badge/Supports_CodeQL_CLI-v2.10.5_--_v2.15-blue) | `v3.7` - `v3.10` | No |
+| `v2.21`          | ![Supports CodeQL CLI v2.9.4 - v2.14](https://img.shields.io/badge/Supports_CodeQL_CLI-v2.9.4_--_v2.14-blue)   | `v3.6` - `v3.9` | No |
+
+See the full list of GHES release and deprecation dates at [GitHub Enterprise Server releases](https://docs.github.com/en/enterprise-server/admin/all-releases#releases-of-github-enterprise-server).
+
 ## Troubleshooting
 
 Read about [troubleshooting code scanning](https://docs.github.com/en/code-security/code-scanning/troubleshooting-code-scanning).