Copy template into each documentation repository, to make it easier for updates to happen

[evilnick]

The vanilla style is currently baked in to template.html. This makes it tricky to keep the docs in sync with theme changes and additions.

Is there a good reason this cant be fetched at build time instead?

[evilnick]

copying in @degville

[nottrobin]

As mentioned in https://github.com/ubuntudesign/meeting-notes/issues/263, we should create issues on all documentation repositories to copy the template from documentation-builder into each local repository, and update the documentation-builder commands to use the --template-path option to override the default template.

[nottrobin]

Added to base squad backlog