docs: move gha into its own files

README.md

@@ -32,7 +32,7 @@ Table of Contents (ToC)
   * [Memcached](docs/Memcached.md)
   * [Google Cloud Storage](docs/Gcs.md)
   * [Azure](docs/Azure.md)
-  * [GitHub Actions](#github-actions)
+  * [GitHub Actions](docs/GHA.md)
 * [Debugging](#debugging)
 * [Interaction with GNU `make` jobserver](#interaction-with-gnu-make-jobserver)
 * [Known Caveats](#known-caveats)
@@ -191,33 +191,6 @@ The default cache size is 10 gigabytes. To change this, set `SCCACHE_CACHE_SIZE`
 The local storage only supports a single sccache server at a time. Multiple concurrent servers will race and cause spurious build failures.
 
 
-### GitHub Actions
-To use the [GitHub Actions cache](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows), you need to set the `SCCACHE_GHA_CACHE_URL`/`ACTIONS_CACHE_URL` and `SCCACHE_GHA_RUNTIME_TOKEN`/`ACTIONS_RUNTIME_TOKEN` environmental variables. The `SCCACHE_` prefixed environmental variables override the variables without the prefix.
-
-In a GitHub Actions workflow, you can set these environmental variables using the following step.
-
-```yaml
-- name: Configure sccache
-  uses: actions/github-script@v6
-  with:
-    script: |
-      core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
-      core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
-```
-
-To write to the cache, set `SCCACHE_GHA_CACHE_TO` to a cache key, for example
-`sccache-latest`. To read from cache key prefixes, set `SCCACHE_GHA_CACHE_FROM`
-to a comma-separated list of cache key prefixes, for example `sccache-`.
-
-In contrast to the [`@actions/cache`](https://github.com/actions/cache) action, which saves a single large archive per cache key, `sccache` with GHA cache storage saves each cache entry separately.
-
-GHA cache storage will create many small caches with the same cache key, e.g. `SCCACHE_GHA_CACHE_TO` and `SCCACHE_GHA_CACHE_FROM`. These GHA caches are differentiated by their [_version_](https://github.com/actions/cache#cache-version). The GHA cache implementation in `sccache` calculates the cache version from the [`sccache` entry key](docs/Caching.md), e.g. the source file path.
-
-For example, if a cache entry has the version `main.rs` and has GHA cache entries for the `sccache-1` and `sccache-2` keys, then `SCCACHE_GHA_CACHE_FROM=sccache-` will match both and [return the most recent entry](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#matching-a-cache-key).
-
-This behavior is useful for scoping caches from different versions of Rust or for cross-platform builds (`rust-sdk-{RUST_TOOLKIT}-{TARGET_TRIPLE}-`), and to allow newer commits to override older caches by adding the Git SHA as a suffix (`-{GITHUB_SHA}`), as in the following screenshot.
-
-<img width="718" src="https://user-images.githubusercontent.com/19253212/205356799-deedc465-e534-4ef6-a249-fc15121fdfd9.png">
 
 ---
 

docs/GHA.md

@@ -0,0 +1,28 @@
+# GitHub Actions
+
+To use the [GitHub Actions cache](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows), you need to set the `SCCACHE_GHA_CACHE_URL`/`ACTIONS_CACHE_URL` and `SCCACHE_GHA_RUNTIME_TOKEN`/`ACTIONS_RUNTIME_TOKEN` environmental variables. The `SCCACHE_` prefixed environmental variables override the variables without the prefix.
+
+In a GitHub Actions workflow, you can set these environmental variables using the following step.
+
+```yaml
+- name: Configure sccache
+  uses: actions/github-script@v6
+  with:
+    script: |
+      core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
+      core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
+```
+
+To write to the cache, set `SCCACHE_GHA_CACHE_TO` to a cache key, for example
+`sccache-latest`. To read from cache key prefixes, set `SCCACHE_GHA_CACHE_FROM`
+to a comma-separated list of cache key prefixes, for example `sccache-`.
+
+In contrast to the [`@actions/cache`](https://github.com/actions/cache) action, which saves a single large archive per cache key, `sccache` with GHA cache storage saves each cache entry separately.
+
+GHA cache storage will create many small caches with the same cache key, e.g. `SCCACHE_GHA_CACHE_TO` and `SCCACHE_GHA_CACHE_FROM`. These GHA caches are differentiated by their [_version_](https://github.com/actions/cache#cache-version). The GHA cache implementation in `sccache` calculates the cache version from the [`sccache` entry key](docs/Caching.md), e.g. the source file path.
+
+For example, if a cache entry has the version `main.rs` and has GHA cache entries for the `sccache-1` and `sccache-2` keys, then `SCCACHE_GHA_CACHE_FROM=sccache-` will match both and [return the most recent entry](https://docs.github.com/en/actions/using-workflows/caching-dependencies-to-speed-up-workflows#matching-a-cache-key).
+
+This behavior is useful for scoping caches from different versions of Rust or for cross-platform builds (`rust-sdk-{RUST_TOOLKIT}-{TARGET_TRIPLE}-`), and to allow newer commits to override older caches by adding the Git SHA as a suffix (`-{GITHUB_SHA}`), as in the following screenshot.
+
+<img width="718" src="https://user-images.githubusercontent.com/19253212/205356799-deedc465-e534-4ef6-a249-fc15121fdfd9.png">