Revert "adding in lesson plan"

See merge request ben/lesson_plan!1

This reverts commit f9d64479

some files get parsed twice and show html in the output.
The solution to this per antora would be to use the partial directory, but his would also require moving all the partial files to partial and modifying the links in the FG and handout OR using partial in the drafting of the FGs.

perhaps a future version will move all of the FG to the partial directory and then the FG, LSAs, and student handouts
would merely include the partial files. not sure if this is better or not. post-processing into antora is actually
looking like it's adding unnecessary complexity. I don't want to layer antora structure on the TD lesson plan structure though
so more discussion necessary to determine what the best way forward is. *some* degree of processing is necessary to split
out the lesson plan, internal, and public pages.

end of week changes. just need to build out the DI2E lesson check on learning and do gitlab build pipeline for all the things