fix: knowledge base source

little snitch/README.md

@@ -1,18 +1,27 @@
 # Little Snitch
 
 1. [Rules](#rules)
+1. [Further readings](#further-readings)
 1. [Sources](#sources)
 
 ## Rules
 
 Available [complete][full ruleset] or in [parts].
 
+## Further readings
+
+- [Little Snitch]
+
 ## Sources
 
+All the references in the [further readings] section, plus the following:
+
 - [Commonly whitelisted domains]
 
 <!-- internal references-->
 [full ruleset]: rules/all.lsrules
+[further readings]: #further-readings
+[little snitch]: ../knowledge%20base/mac%20os%20x/little%20snitch.md
 [parts]: rules/parts/
 
 <!-- external references -->