Fixes to the Tutorial

[egekorkan]

This is an issue will collect noticed problems in the videos. After some time, a republication can be done.

• At https://w3c.github.io/wot-cg/tutorials/whatiswot/docs/preliminary/json-schema/practice at 0:26, the value of the key is not under quotes.
• Binding Templates -> Bindings . This will be with the new publications of the WG.
• Bindings are not in a Bindings Registry
• Video 12 and 13 are not uploaded to YouTube with HD