Add more example notebooks

[freemansw1]

We need to add more example notebooks generally.

• [ ] WRF Example (post v4)
• [ ] GLM Example
• [ ] Radar Example
• [ ] Pretty Plots Examples
• [ ] Merge/split fundamentals
• [ ] Merge/split examples

[w-k-jones]

It would also be nice to add an example showing merges/splits, both in the "fundamentals of detection and tracking" section and as a fully worked example (possibly with radar?)