Add package-build tool definitions

[andrew]

Several operating-system and environment package-build formats are useful tool signals but do not fit the existing language package-manager definitions. Add separate knowledge definitions for them.

• Conda recipe tooling: meta.yaml, meta.yml, recipe/recipe.yaml, and recipe/recipe.yml.
• Arch Linux packaging: .SRCINFO, .AURINFO, and .PKGINFO.
• Debian packaging: debian/control and *.dsc.
• FreeBSD package metadata: +COMPACT_MANIFEST.

Each definition should include a focused fixture and use the package files only where they are a useful tool signal.