MacPorts install guide and Xcode dependency

[contextnerror ​]

I’ve opened a pull request for this (https://github.com/macports/macports-guide/pull/55).
Open to any changes in content or style.

Since I don’t know the specifics for 10.8 and below I haven’t changed any of those.

> On Apr 3, 2023, at 6:26 PM, Joshua Root <jmr at macports.org> wrote:
> 
> On 4/4/2023 10:49, contextnerror wrote:
>> Currently guide.macports.org tells new users to download a full install of Xcode before installing MacPorts. While some ports do require this, most ports still work with just a copy of the command line tools. Should a CLT installation be the recommended method now?
> 
> The recommendation is Xcode + CLTs because that gives the highest chance that things will Just Work. As you note, you might be fine with just the CLTs. You also might be fine with neither if everything you install happens to be available as a binary archive.
> 
> It's fine to expand the explanations in the Guide to cover these complexities, as long as care is taken in how the information is presented. We don't want readers to take away a misleading summary like "The CLTs are all you need."
> 
> - Josh