Update Readme file #334

Updating pyQuARC README File

We need to update the README file before handing off the library to ESDIS. This ticket will be used to document some of the changes that must be implemented into the README file during this PI before closeout.

Word doc: https://docs.google.com/document/d/1HeUYWVaV7uLFZ1JmMhU5AuzhZhrbLS8Sh4P4Qg8BBV4/edit?usp=sharing

• Update the outgoing POC. ESDIS will provide the new contact in the coming days or weeks.
• Update the command python pyQuARC/main.py --file "tests/fixtures/test_cmr_metadata.echo10" to replace .echo10 with echo-c, as the file test_cmr_metadata.echo10 does not exist. The correct file name is test_cmr_metadata.echo-c as noted in the bug report: Test file missing (as per README) #233 (Closed since the bug will be address in this ticket)

The correct command to put in the README file is:
python pyQuARC/main.py --file "tests/fixtures/test_cmr_metadata.echo-c"