Add YAML Input Capability #455
Description
YAML Ain't Markup Language (YAML) provides a useful alternative to JSON scripts, allowing comments and enabling more readable/sharable input files.
Slight adjustments to MissionSim.py and exosims-run would be necessary to allow the YAML input files. In MissionSim.py, the specfile checks should account for different file types and no longer raise a generic JSON error when reading fails.