Clean out obsolete documentation artifacts

[nwhittaker]

Per discussion w/ @TheBlueDog:

• [ ] Remove all markdown files in docs/source/get-started/.
• [ ] Reflect the above removals in the acetate and table_of_contents.yml configs.
• [ ] Remove any related node/bower dependencies.

Is this accurate @TheBlueDog? Anything else?

EDIT: Add node/bower item.

[TheBlueDog]

This is correct. You can remove any related node/bower modules as well.