Add approach to override default names

[wcoder]

via options:

hljs.initLangOnLoad({
    overrideNames: {
		cs: "C-Sharp",
        csharp: "C-Sharp",
		fs: "F-Sharp",
	}
});

via HTML:

<pre>
    <code data-lang-name="C-Sharp">
    ...
    </code>
</pre>