raylib-d v4.2.1 - introducing install script

[Steven Schveighoffer]

Hi everyone,

I've released version 4.2.1 of raylib-d. This version is an attempt to 
fix the issues with linking on Windows.

It introduces a new subproject, `raylib-d:install`, which will copy a 
pre-built binary library of the appropriate version to your project 
directory. While this is far from complete, it provides a required 
feature for Windows. Namely, a fix for a faulty bug in the new symbol 
introduced for raylib 4.2.0 that allows us to validate the binding is 
correct. The symbol I use was not properly exported for the dll version 
of raylib.

I have included in the repository a *correctly* built raylib.dll, which 
now allows linking on Windows.

At present, the only platform supported with the raylib-d:install script 
is Windows on X86_64. If you need a pre-build binary for your platform, 
please open an issue. Note the docs say I have binaries for MacOS x86_64 
and arm64, but these are not working at the moment. There is an issue 
with dub, where it does not properly clone symbolic links, which I 
believe is caused by Phobos std.zip. I will eventually work around this 
issue, and eventually I plan to be smarter about the binary files.

However, for those of you who have wanted to upgrade to raylib-d for 
4.2.0 on Windows, but have ran into linker errors, this is the solution. 
Please read carefully the new README as I have rewritten it to include 
detailed instructions (including how to run the new install script)

I expect a further release to fix the issues with installing MacOS 
binaries soon.

-Steve

https://code.dlang.org/packages/raylib-d
https://github.com/schveiguy/raylib-d/blob/master/README.md