Added bug bounty program

Author: LandauRaz

components/Starknet/modules/tools/nav.adoc

@@ -10,4 +10,5 @@
     ** xref:ref-block-explorers.adoc[Block explorers]
     ** xref:oracles.adoc[Oracles]
     ** xref:data-indexers.adoc[Data indexers]
-    ** xref:audit.adoc[Auditors]
+    ** xref:audit.adoc[Auditors]
+    ** https://immunefi.com/bug-bounty/starknet/information/[Bug bounty program ↗^]