+list + / += Iterable

+CLI app started

docs/Iterator.md

@@ -0,0 +1,29 @@
+# Iterator interface
+
+Iterators are representing the [Iterable] entity, to access its contents
+sequentially. 
+
+To implement the iterator you need to implement only two abstract methods:
+
+## Abstract methods
+
+### hasNext(): Bool
+
+Should return `true` if call to `next()` will return valid next element.
+
+### next(): Obj
+
+Should return next object in the iterated entity. If there is no next method,
+must throw `ObjIterationFinishedError`.
+
+## Usage
+
+Iterators are returned when implementing [Iterable] interface.
+
+## Implemented for classes:
+
+- [List], [Range]
+
+[List]: List.md
+[Range]: Range.md
+[Iterable]: Iterable.md