README: document cache

diff --git a/README.adoc b/README.adoc
index ee56ef01263ccd5c0836ec26064f46864c2339bc..711f96607b751aafb4c21b725e1d2a9a9492f1f4 100644 (file)
--- a/README.adoc
+++ b/README.adoc
@@ -98,6 +98,7 @@ repository.
     [[Jobs]]
     Image = "golang:1.25"
     Script = "./ci/run"
+    Cache = true
 
 An unlimited number of jobs can be configured. They are run in sequence. A
 failed job doesn't stop the following jobs from starting.
@@ -106,6 +107,12 @@ failed job doesn't stop the following jobs from starting.
 strings). If no shebang is present then `#!/bin/sh` is prepended. Otherwise
 the existing shebang is used.
 
+`Cache` can be used to configure a persistent cache for each job. The cache is
+mounted in the container at `/punyci-cache` and must be manually used. For
+example by symlinking into it (e.g. `ln -s /punyci-cache /root/.cache`) at the
+beginning of the CI script. The cache is stored as `punyci-cache-$job` in the
+(bare) repository.
+
 
 == Licenses