Build Documentation review

[cppcooper]

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I've read through the build documentation and made some notes. Some changes, some things that should be discussed a bit.

Here they are:

Dependencies
    Build Dep.
        cmake minimum version number (I believe ab9rf mentioned a minimum version recently, 3.21 I think)
        Perl version? (v5 going by the windows section)
            add sub-items for the XML packages?
        Python version?
        
        link to architectural documentation and diagrams
            `architectural documentation & diagrams` (probably this one)
            `architectural documentation`
            `documentation & diagrams`
        
        Turn the SDL/Perl-package write-ups into annotations

    Installing
        Linux
            The paragraph about needing cmake before you can build anything is probably a bit unnecessary
            
            pthread, this isn't needed for mac as well?
            
            32-bit Binaries
                "installing a 32-bit GCC" (probably should drop the 'a')
        Windows
            Manually
                Perl
                    "existing cmd.exe windows" => "existing command line windows" (cause git-bash, powershell, etc. are things)
                Build Tools
                    "to login to" => "to log into" (looked this up, and the grammar folks say it should be "log in to", so both instances need changing)
                    "- as of writing this is" this reads awkwardly

Compilation
    immediately linking to "Installing DFHack" on the compilation page is a bit weird. It should at least come after the "if you are a DFHack end-user..."
    
    "Note" (at the bottom of the write-up) should probably be in bold, or an annotation
    
    How to get the code
        "instructions for installing git can be found in the platform-specific sections below" no longer the case, needs a link to the dependencies page
        
        "reach out to us for assistance" needs a link to the support page (or whichever page links our discord)
        
        "Failing to keep submodules in sync when switching between branches can result in build errors or scripts that don’t work" bold this
        
    All Platforms
        ";thought the Windows section below" typo
        
        "read the section about getting the code" => "read the section above about getting the code"
        
    Linux
        Build
            " # or ninja -jX" should probably mention the default behaviour
            
            "cmake-friendly IDE like KDevelop 4 or the cmake-gui program." could mention clion (I'll be happy to help over discord)
            
    macOS
        "DFHack functions similarly on macOS and Linux" link to the linux section
        
        "can officially be built on macOS only with" => "can only be built on macOS with"
        
Build Options
    "There are a variety of other settings" => "In addition to what you'll find on this page, there are..."
    
    typical usage, swap the order of the `./` and `../`
    
    The order of options should change. Probably Library would go last, Testing second to last. And the rest don't change.

[cppcooper]

Having just tried out the docker instructions for cross compiling. The commands should probably have sudo as necessary (or $/#). I've seen, so far, that docker build . does need sudo. We shouldn't be relying on the commands returning "permission denied" to provide this necessary information.

[myk002]

sudo is only required if you aren't a member of the docker group. I believe being a member of that group is the standard setup, and when a discussion about this came up on discord, we decided against sudo. It would be fine to mention it, though, for users with different setups.

[myk002]

cmake 3.21 on windows for the VS2022 integration. I believe we support older versions on linux and mac

python 3, but I don't know we have a more specific requirement

otherwise looks good, though I may have comments once I see it in a PR