* rename: branch develop -> main; master -> old-master
* Update all references to `master` and `develop`
* Update the GitHub pages docs
Co-authored-by: Jackson Mills <jmills@ripple.com>, Elliot Lee <intelliot@ripple.com>
* To simplify submit transaction requests by having only one version of them that supports both signed/unsigned transactions, the signed versions of them (submitSigned(), submitSignedReliable()) are deleted.
* Their signed logic is merged into submit() and submitAndWait() (renamed from submitReliable()).
* Change order of submit method params to be consistent.
* Add a SubmitOptions method param to include options for wallet to sign a transaction, and booleans to autofill/failHard a transaction.
