Docs: Clean up reference to custom TLV key for boostagrams

[blastshielddown]

There seems to be some outdated info in the docs for the Value block. Might be helpful to remove the following:

podcast-namespace/value/value.md

Lines 358 to 360 in b9d7dd1

	- There is at least one known shared node ([satoshis.stream](https://satoshis.stream/)) that requires, in addition to
	this specification, the inclusion of the TLV record with type `7629169`, as
	defined [here](blip-0010.md), in order to correctly route the payment to the corresponding receiver

and either reference or bring this appendix up on the page:

podcast-namespace/value/value.md

Lines 495 to 496 in b9d7dd1

	One part of the message is the `extension`, a TLV (Type-Length-Value) stream. Podcast specific data can be added to
	transactions using the key **7629169** with the value described in [bLIP 10](blip-0010.md)