Update Welcome to the Course information

[michaelbnewman]

Regarding the page: /academy/interchain-token-transfer

The link to Running a Relayer is broken: https://build.avax.network/academy/interchain-messaging/10-running-a-relayer/01-running-a-relayer

These is also strange future oriented placeholder text at the bottom of the page that probably needs to be deleted:

We are still working on enabling some features, so in the future you will be able
to evaluate your own understanding of the material through quizzes and claim
a certificate for successful completion at the end.