Docker + WordPress Setup

All the instruction will be found at the link underneath:

https://davidyeiser.com/tutorial/docker-wordpress-theme-setup

When I was installing this, I got this error:

ERROR: Version in "./docker-compose.yml" is unsupported. 
You might be seeing this error because you're using the wrong Compose file version. 
Either specify a version of "2" (or "2.0") and place your service definitions under the `services` key, 
or omit the `version` key and place your service definitions at the root of the file to use version 1.
For more on the Compose file format versions, see https://docs.docker.com/compose/compose-file/

What I did is simple:
I changed the version from ‘3’ to ‘2’

T_T