Build: make bra a local dependency (#17414)

Same idea as with the `gosec`, `revive` and etc.
Allows you to execute `make bra` as pinned local dependency instead
as global one. And therefore alleviates dependency installation issues.

README also updated - I was thinking to provide verbose installation instructions
for it. Since with that way we assume make is installed on the
developer system.

But it might be premature right now?

scripts/go/tools.go

@@ -0,0 +1,9 @@
+// +build tools
+
+package main
+
+import (
+	_ "github.com/Unknwon/bra"
+	_ "github.com/mgechev/revive"
+	_ "github.com/securego/gosec"
+)