Add safe slug generation func in package id

id/random.go

@@ -0,0 +1,12 @@
+package id
+
+import (
+	"fmt"
+	"github.com/writeas/nerds/store"
+)
+
+// GenSafeUniqueSlug generatees a reasonably unique random slug from the given
+// original slug. It's "safe" because it uses 0-9 b-z excluding vowels.
+func GenSafeUniqueSlug(slug string) string {
+	return fmt.Sprintf("%s-%s", slug, store.GenerateRandomString("0123456789bcdfghjklmnpqrstvwxyz", 4))
+}