Change default help arg to -help and mention -h and -? as alternatives

% build/src/bench/bench_bitcoin -h
[...]
  -help
       Print this help message and exit (also -h or -?)

Author: l0rinc

src/common/args.cpp

@@ -688,8 +688,8 @@ bool HelpRequested(const ArgsManager& args)
 
 void SetupHelpOptions(ArgsManager& args)
 {
-    args.AddArg("-?", "Print this help message and exit", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
-    args.AddHiddenArgs({"-h", "-help"});
+    args.AddArg("-help", "Print this help message and exit (also -h or -?)", ArgsManager::ALLOW_ANY, OptionsCategory::OPTIONS);
+    args.AddHiddenArgs({"-h", "-?"});
 }
 
 static const int screenWidth = 79;

test/lint/check-doc.py

@@ -23,7 +23,7 @@
 CMD_GREP_WALLET_HIDDEN_ARGS = r"git grep --function-context 'void DummyWalletInit::AddWalletOptions' -- {}".format(CMD_ROOT_DIR)
 CMD_GREP_DOCS = r"git grep --perl-regexp '{}' {}".format(REGEX_DOC, CMD_ROOT_DIR)
 # list unsupported, deprecated and duplicate args as they need no documentation
-SET_DOC_OPTIONAL = set(['-h', '-help', '-dbcrashratio', '-forcecompactdb'])
+SET_DOC_OPTIONAL = set(['-h', '-?', '-dbcrashratio', '-forcecompactdb'])
 
 
 def lint_missing_argument_documentation():