Bitcoin to NYC3 and update gitian compile code

doc/psbt.md

@@ -1,6 +1,6 @@
 # PSBT Howto for NYC3
 
-Since NYC3 0.17, an RPC interface exists for Partially Signed Bitcoin
+Since NYC3 0.17, an RPC interface exists for Partially Signed NYC3
 Transactions (PSBTs, as specified in
 [BIP 174](https://github.com/bitcoin/bips/blob/master/bip-0174.mediawiki)).
 
@@ -10,7 +10,7 @@ scenarios.
 
 ## PSBT in general
 
-PSBT is an interchange format for Bitcoin transactions that are not fully signed
+PSBT is an interchange format for NYC3 transactions that are not fully signed
 yet, together with relevant metadata to help entities work towards signing it.
 It is intended to simplify workflows where multiple parties need to cooperate to
 produce a transaction. Examples include hardware wallets, multisig setups, and
@@ -18,7 +18,7 @@ produce a transaction. Examples include hardware wallets, multisig setups, and
 
 ### Overall workflow
 
-Overall, the construction of a fully signed Bitcoin transaction goes through the
+Overall, the construction of a fully signed NYC3 transaction goes through the
 following steps:
 
 - A **Creator** proposes a particular transaction to be created. They construct
@@ -32,7 +32,7 @@ following steps:
   partial signature for the inputs for which they have relevant key(s).
 - A **Finalizer** is run for each input to convert the partial signatures and
   possibly script information into a final `scriptSig` and/or `scriptWitness`.
-- An **Extractor** produces a valid Bitcoin transaction (in network format)
+- An **Extractor** produces a valid NYC3 transaction (in network format)
   from a PSBT for which all inputs are finalized.
 
 Generally, each of the above (excluding Creator and Extractor) will simply