display the powers of docker

README.md

@@ -39,6 +39,18 @@ And when pulling, remember to do:
 
 > git pull --recurse-submodules
 
+# Docker
+
+Docker builds the books with a Gitlab pipeline, to check they compile properly.
+
+Docker also lets people build the book with docker from anywhere.
+List any BIND books you want, and build them locally like this:
+
+```bash
+books="core oneshot stories"
+docker run -it --rm --name texbooks andonome/texbind gimme $books
+```
+
 [docs]: https://gitlab.com/bindrpg/config/-/jobs/artifacts/master/raw/docs.pdf?job=build
 [rules]: https://gitlab.com/bindrpg/config/-/jobs/artifacts/master/raw/rules.pdf?job=build
 [resources]: https://gitlab.com/bindrpg/config/-/jobs/artifacts/master/raw/resources.pdf?job=build