Adding content

Chapter 1 : Added identifier for "things".
Chapter 3 : Added material for cloud name, cloud number, references,
peer, inner root nodes.
Added supporting images

Adding image pages for chapter 3
Format updates

1. Linked Chapter 3.
2. Fixed alignment of nodes in the diagrams.
3. Reduced image size for layout consistency.
4. Reformatted text.
Format updates

More formatting updates
Formatting changes

Minor formatting changes
More formatting changes

minor formatting changes
adding a space, and change "references" to lower case