Update the Docs for more clarification on where to start for beginners

[rschwant]

Based on some beginner feedback update the docs with the following to give more instruction for beginners:

1. Under Getting Started titled "Where to Start?" - Add some instructions from the tutorial and how to navigate that below.
2. Under Examples add instructions in Description of Examples add a section "Getting Started By Running Our Examples On Your Own" - Add some instructions and a table about which examples are which and which yaml and jupyter notebooks you should start with.
3. Update the hera specific instructions for user and developer so people know which one to use on cartopy linking files.