Added CI for building/pushing the docker image.

entrypoint

@@ -1,20 +1,18 @@
 #!/bin/bash
+
 # Add local user
-# Either use the PUID/PGID if passed in at runtime or
-# fallback
-
+# Either use the PUID/PGID if passed in at runtime or fallback to 9001.
 USER_ID=${PUID:-9001}
-
 GROUP_ID=${PGID:-$USER_ID}
 echo "Starting with UID : $USER_ID:$GROUP_ID"
 addgroup -g $GROUP_ID proton
 adduser -D -u $USER_ID -G proton -h /var/lib/proton -s /bin/bash proton
 chown -R ${USER_ID}:${GROUP_ID} /var/lib/proton
-
 export HOME=/var/lib/proton
 
-# socat will make the conn appear to come from 127.0.0.1
-# ProtonMail Bridge currently expects that.
+# The ProtonMail Bridge expects connections from 127.0.0.1. Use socat to
+# redirect incoming connections to localhost. Also, this allows us to use
+# the default SMTP/IMAP ports.
 socat TCP-LISTEN:$SMTP_PORT,fork TCP:127.0.0.1:1025 &
 socat TCP-LISTEN:$IMAP_PORT,fork TCP:127.0.0.1:1143 &