Some URLs are broken in `zig cc`: a Powerful Drop-In Replacement for GCC/Clang

Broken links I found white reading the article:
- As always, [Contributions are most welcome](https://github.com/ziglang/zig/blob/master/CONTRIBUTING.md)
- [Here's me using Zig to quickly find out what the maximum UDP packet size is on Linux](https://twitter.com/andy_kelley/status/1242183564512366595).
- [vers.txt](https://github.com/ziglang/zig/blob/master/lib/libc/glibc/vers.txt) - the list of all glibc versions.
- [fns.txt](https://github.com/ziglang/zig/blob/master/lib/libc/glibc/fns.txt) - the list of all symbols that glibc provides, followed by the library it appears in (for example libm, libpthread, libc, librt).
- [abi.txt](https://github.com/ziglang/zig/blob/master/lib/libc/glibc/abi.txt) - for each target, for each function, tells which versions of glibc, if any, it appears in.
- Since Zig already links against Clang libraries for the [translate-c feature](https://ziglang.org/#Integration-with-C-libraries-without-FFIbindings),

BTW, is this still true?
> Linking
> This part is pretty straightforward. Zig depends on LLD for linking rather than shelling out to the system linker, like GCC and Clang do.

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The article was a great read, thank you.
This level of care for the toolchain is beautiful. :^)

I hope you write a blog post as detailed as this one for the build system and package manager.