Tutorial: Send an Issued Token Payment

[mDuo13]

Tutorial for how to send an issued (fungible) token to another account that trusts the same issuer. Not a cross-issuer or cross-currency payment.

This should be slightly harder than "Send XRP" and slightly easier than #1198.

Include steps for troubleshooting common errors like tecPATH_DRY.

Should have working code samples for at least one of xrpl.js or xrpl-py, preferably both.

Bonus points for making it interactive.