docs(readme): update root README to include binary search tree project

Author: singharyan006

README.md

@@ -1,12 +1,13 @@
-# 🧠 Algorithm Practice: Recursion, Sorting, Linked List & HashMap
+# 🧠 Algorithm Practice: Recursion, Sorting, Linked List, HashMap & BST
 
 This project contains fundamental algorithm and data structure implementations, done as part of [The Odin Project](https://www.theodinproject.com/) curriculum.
 
-It focuses on **recursive thinking**, **sorting**, **linked lists**, and now also includes a complete custom-built **hash map** with resizing and collision handling.
+It focuses on **recursive thinking**, **sorting**, **linked lists**, **hash maps**, and now includes a fully-featured **binary search tree** with balance and traversal operations.
 
 ---
 
 ## 📂 Files
+
 ```
 algo-practice/
 ├── recursion/
@@ -23,6 +24,12 @@ algo-practice/
 │ ├── hashMap.js
 │ ├── test.js
 │ └── README.md
+├── binary-search-tree/
+│ ├── Node.js
+│ ├── Tree.js
+│ ├── driver.js
+│ ├── prettyPrint.js
+│ └── README.md
 └── README.md
 ```
 
@@ -47,6 +54,17 @@ algo-practice/
   - Methods like `set`, `get`, `has`, `remove`, `clear`, `keys`, `values`, `entries`
 - Notes + test cases included  
 ➡️ [View detailed HashMap README →](./hashmap/README.md)
+
+### 🌳 `binary-search-tree/`
+- `Node.js` and `Tree.js` → Fully-featured **Balanced BST** implementation
+- `buildTree()` builds a balanced tree from sorted unique array
+- Supports:
+  - `insert()`, `deleteItem()`, `find()`
+  - `height()`, `depth()`, `isBalanced()`, `rebalance()`
+  - Traversals: `inOrder`, `preOrder`, `postOrder`, `levelOrder` with callbacks
+- Includes a `prettyPrint()` visualizer and `driver.js` demo
+➡️ [View detailed BST README →](./binary-search-tree/README.md)
+
 ---
 
 ## 🚀 Sample Inputs & Outputs
@@ -74,8 +92,9 @@ mergeSort([105, 79, 100, 110]);
 ## 🧩 What I Learned
 
 - The difference between iterative vs recursive solutions.
-- How to build data structures from scratch — LinkedList and HashMap.
+- How to build data structures from scratch — LinkedList, HashMap, BST.
 - Handling collisions and resizing logic in hash-based storage.
+- Balancing and traversing binary search trees efficiently.
 - The importance of clear, testable, modular code.
 - How lower-level data structures power high-level abstractions.
 
@@ -84,5 +103,4 @@ mergeSort([105, 79, 100, 110]);
 ## 📄 License
 This project is for educational purposes under the [MIT License](LICENSE).
 
-
 ---