update README

README.md

@@ -9,7 +9,40 @@ inventory, and filter recipes by spirit type, glass, and a search string.
 
 ![Screenshot of the homepage](screenshots/2018-02-22_20:22:45_3200x1800_scrot.png)
 
-## Acquiring cyanide
+More screenshots (which may or may not be out of date) are available in the
+[screenshots directory][screenshots].
+
+## Running cyanide
+
+Cyanide was developed, tested, and is actively used on Linux. It's possible it
+will run without issue on MacOS or Windows, but this hasn't been attempted.
+
+Running concurrent copies of cyanide is not recommended. It could be fine, but
+if data is being modified the changes may not appear across all instances.
+
+Cyanide requires a working PostgreSQL database to store data in. Cyanide
+attempts to create the tables it needs when it is run.
+
+### Docker images
+
+A docker image is available on [quay.io][quay.io]. It uses the default
+configuration shown below, so it'll attempt to connect to a PostgreSQL database
+on `localhost`, using the user `cyanide` and the database `cyanide`. If such a
+database is set up and configured properly, cyanide can be run with the
+following command:
+
+```
+docker run --rm -it --net=host quay.io/dgonyeo/cyanide
+```
+
+A quick explainer on the flags, `--rm` will remove any leftover container once
+cyanide exits (which is fine since all state is stored in PostgreSQL), `-it`
+will make the container interactive and allocate a tty for cyanide to draw to,
+and `--net=host` shares the host's networking with the container, so that
+cyanide will be able to access the database on `localhost`.
+
+To change the database configuration or editor used, it would probably be best
+to mount in a modified config to `/root/.config/cyanide/cyanide.conf`.
 
 ### Binaries
 
@@ -30,24 +63,10 @@ cd cyanide
 stack install
 ```
 
-### Docker images
-
-
-
-## Running cyanide
-
-Cyanide was developed, tested, and is actively used on Linux. It's possible it
-will run without issue on MacOS or Windows, but this hasn't been attempted.
-
-Running concurrent copies of cyanide is not recommended. It could be fine, but
-if data is being modified the changes may not appear across all instances.
-
-### Configuration
-
-Cyanide can be configured via a configuration file stored at
+Once acquired, cyanide must be configured via a configuration file stored at
 `~/.config/cyanide/cyanide.conf`. If this file doesn't exist when cyanide is
-run, the user will be asked if cyanide should create the file. If yes, the
-default contents are:
+run, the user will be asked if it should be created. The default file looks like
+this:
 
 ```
 [DATABASE]
@@ -76,8 +95,11 @@ freely distributed.
 
 ## License
 
-GPLv3
+[GPLv3][licensefile]
 
 [releases]: https://github.com/dgonyeo/cyanide/releases
 [stack]: https://docs.haskellstack.org/en/stable/README/
 [nix]: https://nixos.org/nix/
+[quay.io]: https://quay.io/repository/dgonyeo/cyanide?tag=latest&tab=tags
+[licensefile]: LICENSE
+[screenshots]: screenshots