Provide for docker build and install script

[girish17]

so that one line install is supported through a docker command execution

[alexanderadam]

Is this the official image?
Are there any plans to have automatic builds by version tags (i.e. like this or via GitHub Actions)?

[girish17]

Yes, that's the docker image. The docker images are automatically built on every code commit. GitHub Actions can be tracked here - https://github.com/girish17/op-mattermost/actions

Added @alexanderadam as collaborator.

[girish17]

A year ago the docker auto deploy worked fine. Now, the automatic deployment on docker hub needs Pro subscription. Currently, manual docker build is supported.

[mmospanenko]

will be great to have versioned images on Docker Hub