README: add selftest note and invite setup steps for running locally

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

README.rst

@@ -9,10 +9,6 @@ This project is a simple CI/build bot for patchwork.
 Patchwork is a web interface for patches posted to mailing lists,
 and can also handle test results being reported against said patches.
 
-Currently this project only includes simple checks and build testing,
-all Linux kernel-centric. Patches are not tested against existing
-kernel selftests.
-
 Please see `the wiki <https://github.com/linux-netdev/nipa/wiki>`_
 for how to interact with NIPA.
 
@@ -60,6 +56,22 @@ on which we intend the patches to be applied. NIPA does not know what to reset
 the tree to, it will just try to apply the patches to whatever branch is
 currently checked out in the `$linux` repo.
 
+Setup
+-----
+
+TODO: please open a PR and add package installation and prep needed to run NIPA on your distro of choice.
+
+selftests
+---------
+
+When testing purely selftest patch sets it's useful to skip building the kernel,
+which takes a long time::
+
+  --disable-test patch/build_32bit \
+                 patch/build_allmodconfig_warn \
+		 patch/build_clang \
+		 patch/build_clang_rust
+
 Structure
 =========