Re: [PATCH] gitweb: switch to a modern DOCTYPE

> According to the HTML Standard FAQ:
> 
> 	“What is the DOCTYPE for modern HTML documents?
> 
> 	In text/html documents:
> 
> 		<!DOCTYPE html>
> 
> 	In documents delivered with an XML media type: no DOCTYPE is required
> 	and its use is generally unnecessary. However, you may use one if you
> 	want (see the following question). Note that the above is well-formed
> 	XML.”
> 
> 	Source: [1]
> 
> Gitweb uses an XHTML 1.0 DOCTYPE:
> 
> 	<!DOCTYPE html PUBLIC
> 	"-//W3C//DTD XHTML 1.0 Strict//EN"
> 	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
> 
> While that DOCTYPE is still valid [2], it has several disadvantages:
> 
> 1. It’s misleading. The DTD that browsers are supposed to use with that
>    DOCTYPE has nothing to do with XHTML 1.0 and isn’t available at the URL
>    that is given [2].
> 2. It’s obsolete. XHTML 1.0 was last revised in 2002 and was superseded in
>    2018 [3].
> 3. It’s unreliable. Gitweb uses &nbsp; and &sdot; but lets an external file
>    define them. “[…U]using entity references for characters in XML documents
>    is unsafe if they are defined in an external file (except for &lt;, &gt;,
>    &amp;, &quot;, and &apos;).” [4]
> 
> [1]: <https://github.com/whatwg/html/blob/main/FAQ.md#what-is-the-doctype-for-modern-html-documents>
> [2]: <https://html.spec.whatwg.org/multipage/xhtml.html#parsing-xhtml-documents>
> [3]: <https://www.w3.org/TR/xhtml1/#xhtml>
> [4]: <https://html.spec.whatwg.org/multipage/xhtml.html#writing-xhtml-documents>
> 
> Signed-off-by: Jason Yundt <jason@jasonyundt.email>