rpc: add 2nd arg to signrawtransactionwithkey examples #16210

The RPC examples for signrawtransactionwithkey are missing the 2nd parameter.

Before this change the help text showed:

Examples:
> bitcoin-cli signrawtransactionwithkey "myhex"
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "signrawtransactionwithkey", "params": ["myhex"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/

With the change, it shows:

Examples:
> bitcoin-cli signrawtransactionwithkey "myhex" "[\"key1\",\"key2\"]"
> curl --user myusername --data-binary '{"jsonrpc": "1.0", "id":"curltest", "method": "signrawtransactionwithkey", "params": ["myhex", "[\"key1\",\"key2\"]"] }' -H 'content-type: text/plain;' http://127.0.0.1:8332/

ACK, should be backport I guess.

Do I need to do anything more or can I leave this with you guys? I don't know the correct dance steps to get things merged.

You are good.

Concept ACK

Maybe call example keys: "myprivkeyX" to be slightly more explicit?