packaging: build recipes for arch, gentoo, nix, void, fedora

Five distro recipes in packaging/, all following the same recipe:
unpack the Gitea release archive (which extracts to fastwc/), run
autoreconf -fi (the generated configure/Makefile.in are not committed),
configure, make, make install - the binary needs only glibc.

Each recipe notes the release prerequisite: the archive URL requires a
v0.1.0 tag on the remote, and Arch/Nix/Void carry an integrity
placeholder to fill in once the tag exists. The PKGBUILD was validated
with makepkg --printsrcinfo, and the full build recipe was run
end-to-end from a Gitea-layout tarball (autoreconf, configure, make,
make install DESTDIR) producing a working /usr/bin/fastwc.

packaging/void/template

@@ -0,0 +1,18 @@
+# Template file for 'fastwc'
+pkgname=fastwc
+version=0.1.0
+revision=1
+build_style=gnu-configure
+hostmakedepends="autoconf automake libtool"
+short_desc="A wc replacement that beats GNU wc - SIMD kernels, mmap, threads"
+maintainer="huntedbytheirs <[email protected]>"
+license="MIT"
+homepage="https://git.spectoria.dev/huntedbytheirs/fastwc"
+# requires a v0.1.0 tag on the Gitea remote; replace SKIP with the real
+# checksum once the tag exists (xbps-src prints it on the first attempt)
+distfiles="https://git.spectoria.dev/huntedbytheirs/fastwc/archive/v${version}.tar.gz"
+checksum=SKIP
+
+pre_configure() {
+	autoreconf -fi
+}