docs: describe published images

README.md

@@ -5,7 +5,7 @@ Proposals run or planned for Mainnet (agoric-3)
 This repo serves several functions:
 
 - verify building an image with in which known proposals have executed
-- publishing an image with all passed proposals (TODO: https://github.com/Agoric/agoric-3-proposals/issues/6)
+- publishing an image with all passed proposals
 - verify that certain tests pass after each proposal
 
 # Design
@@ -52,6 +52,8 @@ If the proposal is _pending_ and does not yet have a number, use a letter. The p
 
 # Usage
 
+## Development
+
 To build the test images,
 
 ```
@@ -72,8 +74,31 @@ To run the tests for particular proposals,
 ./runTestImages.ts --match upgrade
 ```
 
+## Contributing
+
 To add a proposal, see [./CONTRIBUTING.md]
 
+## Images
+
+This repo publishes an image of the synthetic agoric-3 chain with all proposals that have "passed" (defined in this repo as having a proposal number).
+
+The CI builds on every push to the trunk branch, (`main`), or a PR branch. You can view all versions at https://github.com/agoric/agoric-3-proposals/pkgs/container/agoric-3-proposals/versions
+
+The versions built from the main branch are at: `ghcr.io/agoric/agoric-3-proposals:main`. For each PR, they're at a URL like `ghcr.io/agoric/agoric-3-proposals:pr-11`.
+
+If you RUN this image, you'll get a working chain running `agd` until you terminate,
+
+```sh
+docker run ghcr.io/agoric/agoric-3-proposals:main
+```
+
+Or locally,
+
+```
+docker build -t ghrc.io/agoric/agoric-3-proposals:dev .
+docker run  ghrc.io/agoric/agoric-3-proposals:dev
+```
+
 ## Future work
 
 - [ ] include a way to test soft patches that weren't proposals (e.g. PismoB)