Create fre/cmor/README.md

[ilaflott]

Describe your changes

adds back in old notes from original author's usage into cmor specific README.

no functionality changes. pipelines will be cancelled.

[ceblanton]

I'm not sure these old notes are helpful... @Ciheim what do you think? We need some fresh cmor usage docs anyway

[ceblanton]

On second thought, if those examples were rephrased in fre-cli syntax (fre cmor run blah blah) and showed how to get the input files (instead of assuming they are there), it would be very useful.

[ilaflott]

> On second thought, if those examples were rephrased in fre-cli syntax (fre cmor run blah blah) and showed how to get the input files (instead of assuming they are there), it would be very useful.

this is sort of what i was thinking. Also- i had actually meant to put these notes in fre cmor's README in the first place, when i was doing some clean up items suggested by pylint.

[ceblanton]

@Ciheim, after you return let's clean up Sergey's old usage examples with the new syntax, and explain how to get the input config files.

[ilaflott]

let's just get this in, and start up a new PR/branch with CMOR doc edits to this README nugget

[ilaflott]

ready to go

[ceblanton]

the usage syntax needs to be updated but otherwise it's useful