doc: improve godoc of top level 'testify' package

doc.go

@@ -1,15 +1,17 @@
-// Package testify is a set of packages that provide many tools for testifying that your code will behave as you intend.
+// Module testify is a set of packages that provide many tools for testifying that your code will behave as you intend.
 //
-// testify contains the following packages:
+// Testify contains the following packages:
 //
-// The assert package provides a comprehensive set of assertion functions that tie in to the Go testing system.
+// The [github.com/stretchr/testify/assert] package provides a comprehensive set of assertion functions that tie in to [the Go testing system].
+// The [github.com/stretchr/testify/require] package provides the same assertions but as fatal checks.
 //
-// The mock package provides a system by which it is possible to mock your objects and verify calls are happening as expected.
+// The [github.com/stretchr/testify/mock] package provides a system by which it is possible to mock your objects and verify calls are happening as expected.
 //
-// The suite package provides a basic structure for using structs as testing suites, and methods on those structs as tests.  It includes setup/teardown functionality in the way of interfaces.
+// The [github.com/stretchr/testify/suite] package provides a basic structure for using structs as testing suites, and methods on those structs as tests.  It includes setup/teardown functionality in the way of interfaces.
 //
 // A [golangci-lint] compatible linter for testify is available called [testifylint].
 //
+// [the Go testing system]: https://go.dev/doc/code#Testing
 // [golangci-lint]: https://golangci-lint.run/
 // [testifylint]: https://github.com/Antonboom/testifylint
 package testify