docs: add sample-tapd.conf

[Roasbeef]

Generated by Claude 3.5 Sonnet, should spot check accordingly.

[guggero]

Very nice!

Added some extra information and updated some values to look more similar to lnd's sample conf, then also added the check script we have.

[HannahMR]

It would be great to add a bit of guidance on when config needs to be in the tapd.conf file and when it needs to be in the lit.conf file.

[Liongrass]

The only thing I found unclear about this configuration file was the RFQ section at the very bottom.

For example, does use_mock_price_oracle_service_promise_to_not_use_on_mainnet (lol) require a boolean or not?

And the next line, if I want to use the mock price oracle, do I also need to set experimental.rfq.priceoracleaddress=?

And finally I might benefit from having an example what a USD per sat rate would look like, especially since the configuration reads "cent per sat" but the description reads "USD per sat". 1 sat is currently 0.00061 USD, would I then enter 0.00061 below?

experimental.rfq.mockoraclecentpersat=0.00061

[guggero]

use_mock_price_oracle_service_promise_to_not_use_on_mainnet is the value you set for the key experimental.rfq.priceoracleaddress=.
So:

experimental.rfq.priceoracleaddress=use_mock_price_oracle_service_promise_to_not_use_on_mainnet

And yes, it's that verbose on purpose.

[guggero]

It would be great to add a bit of guidance on when config needs to be in the tapd.conf file and when it needs to be in the lit.conf file.

If things run within litd, all config values need to be in lit.conf, but prefixed with the service (so in this case taproot-assets.xxx. I think that's generally explained here: https://github.com/lightninglabs/lightning-terminal/blob/master/docs/config-lnd-integrated.md#use-a-configuration-file

Not sure if this explanation should go into sample-tapd.conf, since that doesn't necessarily directly relate to litd. So maybe that should be described in a general "how to use the taproot assets channel feature in litd" document?