update TOC, add all classes/interfaces before final typeup

study/COLLECTIONS.MD

@@ -14,6 +14,25 @@ This page will be using [javaTpoint](https://www.javatpoint.com/collections-in-j
     - [Table of Contents](#table-of-contents)
     - [Hierarchy of Collection Framework](#hierarchy-of-collection-framework)
     - [Methods of the Collection Interface](#methods-of-the-collection-interface)
+    - [Interfaces](#interfaces)
+        - [Iterator Interface](#iterator-interface)
+        - [Iterable Interface](#iterable-interface)
+        - [Collection Interface](#collection-interface)
+        - [List Interface](#list-interface)
+        - [Queue Interface](#queue-interface)
+        - [Deque Interface](#deque-interface)
+        - [Set Interface](#set-interface)
+        - [SortedSet Interface](#sortedset-interface)
+    - [Classes](#classes)
+        - [ArrayList Class](#arraylist-class)
+        - [LinkedList Class](#linkedlist-class)
+        - [Vector Class](#vector-class)
+        - [Stack Class](#stack-class)
+        - [PriorityQueue Class](#priorityqueue-class)
+        - [ArrayDeque Class](#arraydeque-class)
+        - [HashSet Class](#hashset-class)
+        - [LinkedHashSet Class](#linkedhashset-class)
+        - [TreeSet Class](#treeset-class)
 
 <!-- /TOC -->
 
@@ -49,4 +68,42 @@ All datastructures referenced here can be imported using `import java.util.<stru
 
 Since all classes discussed onward inherit the `Collections` interface, you can be sure that a valid, working implementation exists for every single one of these methods.
 
-However, the real power comes from the next set of interfaces, and the special methods devised by each class to manipulate these complex data structures.
+However, the real power comes from the next set of interfaces, and the special methods devised by each class to manipulate these complex data structures.
+
+## Interfaces
+
+### Iterator Interface
+
+### Iterable Interface
+
+### Collection Interface
+
+### List Interface
+
+### Queue Interface
+
+### Deque Interface
+
+### Set Interface
+
+### SortedSet Interface
+
+## Classes
+
+### ArrayList Class
+
+### LinkedList Class
+
+### Vector Class
+
+### Stack Class
+
+### PriorityQueue Class
+
+### ArrayDeque Class
+
+### HashSet Class
+
+### LinkedHashSet Class
+
+### TreeSet Class