Add version to compose file instead of talking about it

README.md

@@ -47,14 +47,6 @@ docker buildx build --load -t 1337kavin/sponsorblock-mirror .
 
 * If Docker complains that `the --mount option requires BuildKit`, make sure you are building with `docker buildx build` and not `docker build`.
 
-* If `docker compose` complains like this:
-  ```
-  ERROR: The Compose file './docker-compose.yml' is invalid because:
-  Unsupported config option for volumes: 'postgres_data'
-  Unsupported config option for services: 'sb-mirror'
-  ```
-  then you are using an old version of `docker compose` which does not fully support the Compose Specification and [requires a 'version' key to differentiate the file from a V1 compose file](https://docs.docker.com/compose/compose-file/#version-top-level-element). Try appending `version: "3"` to the file.
-
 * To access the PosgresQL database directly, you can `docker exec -ti postgres-sb-mirror bash -c 'psql $POSTGRES_DB $POSTGRES_USER'`.
 
 * Requests for videos not in the database are forwarded to `https://sponsor.ajay.app/`, which may be down or malfunctioning. A response of the string `Internal Server Error` is likely to be from there, rather than from this application.

docker-compose.yml

@@ -39,3 +39,4 @@ services:
       - sb-mirror
 volumes:
   postgres_data: null
+version: "3"