Add hack for supporting help in Firefox

The Firefox console includes a function aliases as `help`. This
alias is read-only, and, thus, the REPL `help()` function is not
available. As a workaround, we need to use another alias. The
least painful solution seemed to be adding an underscore prefix,
even though is not optimal. Browsers. *sigh*

Author: kgryte

lib/node_modules/@stdlib/repl/scripts/browser.js

@@ -72,7 +72,8 @@ function main() {
 
 	// Create an object tree from value aliases...
 	tmp = {
-		'help': help
+		'help': help,
+		'_help': help // Firefox devtools already aliases `help` (and `?`) to a read-only value :(
 	};
 	paths = [];
 	for ( i = 0; i < NAMESPACE.length; i++ ) {