This adapts the merged website repository to use the image and bazel
build framework. It explicitly avoids the container_image rules provided
by bazel, opting instead to build with direct docker commands when
necessary.
The relevant build commands are incorporated into the top-level
Makefile.
This will allow us to merge the site into the main repository.
This merge allows the documentation to be kept up-to-date and
synchronized with the main project. Builds will be triggered on any
update, removing the need for the cron-based reploy.