add to readme description of what's in each directory

[edwardhartnett]

For the readme, what are the contents of the different subdirectories:

• ecf ?
• fix - some data files?
• jobs ?
• modulefiles - module files for NOAA HPC systems
• parm ?
• scripts?
• sorc ?
• tests - unit tests for rrfs-workflow code
• ush?
• versions - shell scripts setting environment vars to the required versions of all dependencies, for building and for running rrfs-workflow.

[MatthewPyle-NOAA]

Here are a few - will provide more background on a few more in a subsequent comment.

ecf - contains the ecFlow contents which will drive the RRFS workflow in NWS operations.

fix - contains static data

jobs - contains the main driver scripts (known as J-jobs) for each task. The workflow driver (either ecFlow or rocoto) submits these J-jobs,

parm - parameter files - generally namelists or configure files

[MatthewPyle-NOAA]

scripts - the "ex scripts" - the primary script for a given task, and called by the J-job.

sorc - all of the source codes that need to be built/compiled for use within the package

ush - the utility scripts - scripts typically called by the "ex scripts" to handle specific tasks, often repeatedly for different times or geographic regions.

Want to bring in @BenjaminBlake-NOAA to see if he has any additional perspective to add. And can point you at the NCO implementation standard (https://www.nco.ncep.noaa.gov/idsb/implementation_standards/ImplementationStandards.v11.0.0.pdf) which describes most of these items in Table 3 on p. 19.

[BenjaminBlake-NOAA]

Thanks @MatthewPyle-NOAA and @edwardhartnett . These descriptions sound pretty good to me.