Version control of configuration YAML files

[zacsimile]

There are quite a few commits changing the configuration YAML files, and this can lead to/has led to issues where ETL constants and/or hardware configurations have changed on the instrument computer based on changes from another machine. Two potential options:

1. .gitignore the configuration YAMLs, and only ship example_config.yaml, example_experiment.yaml, etc. with the software
2. Switch the read/write location of the YAMLs to somewhere like AppData/.ASLM (Windows)/~/.ASLM (Mac/Linux) and leave the YAMLs where they currently are as examples

I prefer (2).

[AdvancedImagingUTSW]

Go with your preference.

[zacsimile]

Done in #179. Configuration files are now stored in AppData/.ASLM/config on Windows or ~/.ASLM/config on Mac/Linux.