Update docs to reflect segwit support in Stacks 2.1

stackslib/src/chainstate/stacks/boot/docs.rs

@@ -33,7 +33,7 @@ This is the self-service interface.  tx-sender will be the Stacker.
 * You will need the minimum uSTX threshold. This isn't determined until the reward cycle begins, but this
    method still requires stacking over the _absolute minimum_ amount, which can be obtained by calling `get-stacking-minimum`.
 * The pox-addr argument must represent a valid reward address.  Right now, this must be a Bitcoin
-p2pkh or p2sh address.  It cannot be a native Segwit address, but it may be a p2wpkh-p2sh or p2wsh-p2sh address.
+p2pkh or p2sh address.  // As of Stacks 2.1, native Segwit addresses are supported. However, the address may still be a p2wpkh-p2sh or p2wsh-p2sh type.
 
 The tokens will unlock and be returned to the Stacker (tx-sender) automatically."),
         ("revoke-delegate-stx", "Revoke a Stacking delegate relationship. A particular Stacker may only have one delegate,