Please incorporate FreqFun Book in the gallery

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Please note: before filling out this template, make sure that your JupyterBook is built and published.

1. Name of the repository: FreqFun
2. Repo url: https://github.com/LinkedEarth/FreqFun
3. Branch: master
4. Url of .config.yml: https://github.com/LinkedEarth/FreqFun/blob/master/myst.yml
5. Host for the JupyterBook: https://linked.earth
6. User: LinkedEarth
7. Landing suffix (name of the page you want users to land on):
8. Landing page url: https://linked.earth/FreqFun/