Improvements to online search setup

[wbenoit26]

We (likely) won't be making any changes to the online search initialization process for a little while, so this issue is to document improvements we want to make in the future.

1. More documentation to the aframe-init script
2. Option to specify Aframe run directory for copying weights and data
3. Option to specify paths to AMPLFI checkpoints
4. Make it clear that the config.yaml and prior.yaml files should be updated based on how Aframe/AMPLFI were trained
5. Stop monitoring script from crashing when the output/events directory doesn't exist yet