IndexedMerkleTree (#174)

* Draft IndexedMerkleTree

* First IndexedMerkleTree implementation

* Add getProof and verifyProof logic

* Fix getProof function

* Finish TS IndexedMerkleTree implementation & add some unit tests

* Add Bytes32IndexedMerkleTree and AddressIndexedMerkleTree

* Add update logic to the IndexedMerkleTree library

* Add custom hash functions logic

* Add natspec comments

* Update CHANGELOG, README and add some comments

* fix changelog

---------

Co-authored-by: Artem Chystiakov <artem.ch31@gmail.com>
Co-authored-by: Artem Chystiakov <47551140+Arvolear@users.noreply.github.com>

Author: Hrom131

CHANGELOG.md

@@ -1,8 +1,8 @@
 # Changelog
 
-## [none]
+## [patch]
 
-- Fixed deprecation warnings.
+- Added `IndexedMerkleTree` library that implements Indexed Merkle Tree data structure.
 
 ## [3.3.2]
 

README.md

@@ -72,6 +72,7 @@ contracts
 │   │   ├── CartesianMerkleTree — "CMT reference implementation"
 │   │   ├── DynamicSet — "Set for strings and bytes"
 │   │   ├── IncrementalMerkleTree — "IMT implementation with flexible tree height"
+│   │   ├── IndexedMerkleTree — "IndexedMT implementation"
 │   │   ├── PriorityQueue — "Max queue heap implementation"
 │   │   ├── SparseMerkleTree — "SMT optimized implementation"
 │   │   └── memory