📜 Legal docs to support CC BY-SA 4.0

[JFWooten4]

Need to rework internal agreement docs (most likely path is to just open source them). These reworks should ensure:

• Issuer materials are licensed to the Syndicate for perpetual royalty-free use
• Materials can be made available to the public under the CC BY-SA 4.0 license
• Minor things about any data access charges or central APIs offered for investors

Then we can make the code for the repo itself Affero and the rest of the content under:

[JFWooten4]

Partially addressed by 2701acb
(still needs backdating info from existing users)

[JFWooten4]

Please let's also standardize the file paths to no longer include underscores or capital letters like in stellar/stellar-docs#2231.