repo: MAINTAINERS instructions for multi pills

MAINTAINERS.md

@@ -159,6 +159,37 @@ so that I can type e.g. `git mu origin/foo 1337`.
 
 If you're making a Vere release, just play it safe and update all the pills.
 
+To produce multi pills, you will need to set up an environment with the
+appropriate desks with the appropriate contents, doing something like the
+following (where `> ` denotes an urbit command and `% ` denotes a unix shell
+command):
+
+```console
+> |merge %garden our %base
+> |merge %landscape our %base
+> |merge %bitcoin our %base
+> |merge %webterm our %base
+% rsync -avL --delete pkg/arvo/ zod/base/
+% for desk in garden landscape bitcoin webterm; do \
+    rsync -avL --delete pkg/$desk/ zod/$desk/ \
+  done
+> |commit %base
+> |commit %garden
+> |commit %landscape
+> |commit %bitcoin
+> |commit %webterm
+> .multi/pill +solid %base %garden %landscape %bitcoin %webterm
+> .brass-multi/pill +brass %base %garden %landscape %bitcoin %webterm
+```
+
+And then of course:
+
+```console
+> .solid/pill +solid
+> .brass/pill +brass
+> .ivory/pill +ivory
+```
+
 For an Urbit OS release, after all the merge commits, make a release with the
 commit message "release: urbit-os-v1.0.xx".  This commit should have up-to-date
 artifacts from pkg/interface and a new version number in the desk.docket-0 of