Update Docker Install Docs

[tucker19]

Describe the bug Current Docker-Compose docs have a build section, keeping this in tries to build the project without pulling the image and just spins. This is the case where the repo has not been cloned

To Reproduce Steps to reproduce the behavior:

1. Create/edit your docker-compose.yml
2. do docker-compose up grimoire
3. Just see a Building message with nothing being built

Expected behavior Either need to clone repo and remove image for build section to work or vice versa

Additional context Just wanting to help with docs and make sure no one else has issues