docs: fix experimental features toc

License: MIT
Signed-off-by: Adrian Lanzafame <adrianlanzafame92@gmail.com>

docs/experimental-features.md

@@ -21,6 +21,9 @@ the above issue.
 - [Private Networks](#private-networks)
 - [ipfs p2p](#ipfs-p2p)
 - [Circuit Relay](#circuit-relay)
+- [Plugins](#plugins)
+- [Directory Sharding / HAMT](#directory-sharding-hamt)
+- [IPNS PubSub](#ipns-pubsub)
 
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