Add some comments

.build.yml

@@ -12,13 +12,22 @@ packages:
   - runit
 
 tasks:
+  # add the "build" user to the docker group
+  # start the docker service
+  # briefly pause to allow the docker service to fully start
   - prep: |
       sudo addgroup build docker 
       sudo rc-service docker start
       sleep 4
+
+  # build the image using the just recipe
   - build: |
       cd alpine-cli
       just build
+
+  # set environment variables from the ~/.envdir directory
+  # see http://smarden.org/runit/chpst.8.html for details on chpst
+  # publish the image using the just recipe
   - publish: |
       cd alpine-cli
       chpst -e ~/.envdir just publish