Update docs in onestop-clients

[erinreeves]

Summary

As a	onestop-python-client user
I want to be able to	be able to understand how to setup and use the onestop-python-client
So that I can	use onestop-python-client

• Move readme's scattered into the docs folder.
• Create root readme in docs folder.
• Remove information about loading data into OneStop and link more info link to OneStop or the test-data repo.
• Create a general build section briefly commenting about the current process.

[erinreeves]

cedardevs/onestop-clients#59