Update 'Home'

Home.md

@@ -25,7 +25,11 @@ Location is entirely cosmetic so I've decided that adding complexity to optional
 
 ### How do I set global configuration options?
 
-Through the environment. For example, to set `SELF_URL_PATH`, add the following to `.env`:
+There are two sets of options you can change through the environment - options specific to tt-rss (those are prefixed with `TTRSS_`) and options affecting container behavior.
+
+#### Options specific to tt-rss
+
+For example, to set tt-rss global option `SELF_URL_PATH`, add the following to `.env`:
 
 ```ini
 TTRSS_SELF_URL_PATH=http://example.com/tt-rss
@@ -35,6 +39,13 @@ Don't use quotes around values. Note the prefix (`TTRSS_`) before the value.
 
 Look [here](https://tt-rss.org/wiki/GlobalConfig) for more information.
 
+#### Container options
+
+Some options, but not all, are mentioned in `.env-dist`. You can see all available options in the Dockerfile:
+
+- https://dev.tt-rss.org/fox/ttrss-docker-compose/src/branch/static-dockerhub/src/app/Dockerfile#L39 (static)
+- https://dev.tt-rss.org/fox/ttrss-docker-compose/src/branch/master/app/Dockerfile#L28 (dynamic)
+
 ### How do I customize the YML without commiting my changes to git?
 
 You can use [docker-compose.override.yml](https://docs.docker.com/compose/extends/). For example, customize `db` to use a different postgres image: