Add testifylint to godocs too

I checked the render locally.

doc.go

@@ -8,4 +8,9 @@
 // The 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.
+//
+// A [golangci-lint] compatible linter for testify is available called [testifylint].
+//
+// [golangci-lint]: https://golangci-lint.run/
+// [testifylint]: https://github.com/Antonboom/testifylint
 package testify