New documentation site built with Material for MkDocs

[thobson88]

Closes #173.

New improved documentation.

Note that I hit this issue when adding these lines to mkdocs.yml:

  - pymdownx.emoji:
      emoji_index: !!python/name:material.extensions.emoji.twemoji
      emoji_generator: !!python/name:material.extensions.emoji.to_svg

which are needed to render the copy-to-clipboard icon on the "Getting Started" page. Seems like PyYAML (latest version, 6.0.1) does not consider this valid YAML. My workaround is to set the --unsafe flag on the check-yaml pre-commit hook.

[sgreenbury]

Could exclude instead though I think this is the only yml in the repo so the --unsafe flag seems better

Suggested change

	args: [--unsafe]
	exclude: mkdocs\.yml

[sgreenbury]

Looks good to me!