add IOOS header and footer

[MathewBiddle]

Example:
https://ioos-ui-components.s3.us-east-1.amazonaws.com/compact-header.html

[ocefpaf]

This is not implemented in sphinx-book-theme, and jupyter-book has no option for it. See executablebooks/sphinx-book-theme#559

A very inelegant solution would be to override every HTML created and add the header line needed. (The JS is actually easy and we don't even need to use the CDN URL. We can ship it with our build to make it faster.)

<ioos-header variant="compact"></ioos-header>

Here is how it would kook like.