Merge #15760: doc: Clarify sendrawtransaction::maxfeerate==0 help

fa49db7 doc: Clarify sendrawtransaction::maxfeerate==0 help (MarcoFalke)

Pull request description:

  Used a lot in e.g. the tests: `git grep 'maxfeerate=0)' test`

ACKs for commit fa49db:
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Tree-SHA512: cb3fa10960f45606c3599b76c48666a663e5c44cfb7c29bab5d44caa7dc6cb57aaac81cb9b173e079dde01d07c5363c99416f25303a8fd41010928118474a741

Author: MarcoFalke

src/rpc/rawtransaction.cpp

@@ -1054,7 +1054,9 @@ static UniValue sendrawtransaction(const JSONRPCRequest& request)
                 "\nAlso see createrawtransaction and signrawtransactionwithkey calls.\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of the raw transaction"},
-                    {"maxfeerate", RPCArg::Type::AMOUNT, /* default */ FormatMoney(DEFAULT_MAX_RAW_TX_FEE), "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT + "/kB\n"},
+                    {"maxfeerate", RPCArg::Type::AMOUNT, /* default */ FormatMoney(DEFAULT_MAX_RAW_TX_FEE),
+                        "Reject transactions whose fee rate is higher than the specified value, expressed in " + CURRENCY_UNIT +
+                            "/kB.\nSet to 0 to accept any fee rate.\n"},
                 },
                 RPCResult{
             "\"hex\"             (string) The transaction hash in hex\n"