Update the docs for tests[n].package_contents.lib

[multimeric]

The current instructions are slightly inaccurate. I've updated it based on reading this section:

rattler-build/crates/rattler_build_core/src/package_test/content_test.rs

Lines 230 to 297 in d3e2b4b

	Section::Lib => {
	let raws = if exists {
	self.lib.exists.include_globs()
	} else {
	self.lib.not_exists.include_globs()
	};
	if target_platform.is_windows() {
	Self::match_files(raws, |raw| {
	let mut res = Vec::new();
	if raw.ends_with(".dll") {
	res.push((
	raw.to_string(),
	GlobSet::builder()
	.add(Glob::new(&format!("Library/bin/{raw}"))?)
	.build()?,
	));
	} else if raw.ends_with(".lib") {
	res.push((
	raw.to_string(),
	GlobSet::builder()
	.add(Glob::new(&format!("Library/lib/{raw}"))?)
	.build()?,
	));
	} else {
	res.push((
	raw.to_string(),
	GlobSet::builder()
	.add(Glob::new(&format!("Library/bin/{raw}.dll"))?)
	.build()?,
	));
	res.push((
	raw.to_string(),
	GlobSet::builder()
	.add(Glob::new(&format!("Library/lib/{raw}.lib"))?)
	.build()?,
	));
	}
	Ok(res)
	})
	} else {
	Self::match_files(raws, |raw| {
	let globset = if target_platform.is_osx() {
	if raw.ends_with(".dylib") || raw.ends_with(".a") {
	GlobSet::builder()
	.add(Glob::new(&format!("lib/{raw}"))?)
	.build()
	} else {
	GlobSet::builder()
	.add(build_glob(format!("lib/{{,lib}}{raw}.dylib"))?)
	.add(build_glob(format!("lib/{{,lib}}{raw}.*.dylib"))?)
	.build()
	}
	} else {
	if raw.ends_with(".so") || raw.contains(".so.") || raw.ends_with(".a") {
	GlobSet::builder()
	.add(Glob::new(&format!("lib/{raw}"))?)
	.build()
	} else {
	GlobSet::builder()
	.add(build_glob(format!("lib/{{,lib}}{raw}.so"))?)
	.add(build_glob(format!("lib/{{,lib}}{raw}.so.*"))?)
	.build()
	}
	}?;
	Ok(vec![(raw.to_string(), globset)])
	})
	}
	}

I think that further improvements might also be possible, but I didn't want to try anything further without discussion. Using comments in the example make it a bit hard to read as it doesn't wrap across lines. Also there is further subtlety which isn't captured in the examples, like the fact adding .dll to the end of the glob will turn off the automatic .lib glob etc.