[FEATURE REQUEST] Improve traceability of shell script variables

[djvaron]

Name and Institution (Required)

Name: Daniel Varon Institution: Harvard University

New IMI feature or discussion

The componentized IMI lacks traceability of variables in component shell scripts. For example, it's unclear from where the i variable is inherited in the kalman.sh function run_period().

Suggested fix is to add comment headers to all shell scripts detailing where variables are defined/inherited. For example, run_inversion.sh currently includes the following comment where the config file is read in:

# Get configuration
#  This defines $StartDate, $EndDate, $nBufferClusters, $RunName, $isAWS
#  It also define $PriorError, $ObsError, $Gamma, $PrecomputedJacobian

[laestrada]

Closing with #159