docs: update README for SPPL usage

README.md

@@ -43,7 +43,7 @@ The command-line application currently supports GenSQL-strict and GenSQL-permiss
 If you would like to use `GenSQL.query` to query SPPL models you will need to ensure that SPPL is on the classpath, and that [libpython-clj](https://github.com/clj-python/libpython-clj) can find a Python where SPPL is installed. The easiest way to accomplish this is to use [Nix](https://nixos.org/):
 
 ```shell
-nix develop github:OpenGen/GenSQL.gpm.sppl -c clj -Sdeps '{:deps {io.github.OpenGen/GenSQL.gpm.sppl {:git/sha "718de40878766bb8d08acc2b429a76ed662a1352"}}}' -M -m gensql.query.main --help
+nix develop '.#sppl' --command clj -M:query-sppl --help
 ```
 
 ### Clojure interface
@@ -150,7 +150,18 @@ If you forget, a CI job will check it for you when you make a pull request.
 
 ```shell
 nix build '.#uber' -o gensql.jar
+# or
+nix build '.#uberGpmSppl' -o gensql-sppl.jar
 ```
 
+#### Building an OCI image (docker container)
+
+```shell
+nix build '.#ociImg' -o gensql.tgz
+# or
+nix build '.#ociImgSppl' -o gensql-sppl.tgz
+```
+
+
 [codecov-url]: https://codecov.io/github/OpenGen/GenSQL.query
 [codecov]: https://img.shields.io/codecov/c/github/OpenGen/GenSQL.query/main.svg?maxAge=3600