Add Docker installation configuration & instructions

[jamietre]

• Revise Dockerfile to work correctly
• Add a build script to build docker image with local user and git info
• Add instructions for standing up http server in Docker
• Discuss considerations for using docker in different operating environments

[jamietre]

This can be improved to set the user's git username/email configuration on startup instead of build, will push another commit shortly. (Edit: Done)