Investigate build issues for tomster-player branch

[Mikek2252]

There are some build issues on the tomster-player branch with the error templateCompiler.registerPlugin is not a function.

The steps on the slide also need to be update to:

git clone https://github.com/simplabs/ember-workshop.git  
git checkout tomster-player
git branch <branchname> step-0
git checkout <branchname>
yarn install --pure-lockfile
cd tomster-player
yarn start

and a note needs to be added that it is incompatible with node 16.