Add workshop support

[tydaytygx]

Support for setting workshop maps in docker-compose.yml

[joedwards32]

Thanks for the contribution! Do you have any suggested updates to README.md to document these options?

[tydaytygx]

Thanks for the contribution! Do you have any suggested updates to README.md to document these options?

Sure, may add workshop guide like this.

Workshop options

Modify docker-compose.yml

Place the map id or collection id like this.

- CS2_HOST_WORKSHOP_MAP=xxxxxx
- CS2_HOST_WORKSHOP_COLLECTION=xxxxxx

Note: the map and collection are two different option.

You could find the id at the workshop item's web url.

For example:
https://steamcommunity.com/sharedfiles/filedetails/?id=xxxxxx