Improve the documentation

[Vishnu-Hacks]

Please improve the documentation, by including a better explanation of working of the compressor and the decompressor. We are a group of students and all are beginners to the open source. It's very hard to understand the working of the code, with the existing documentations. The Readme files only tell about the block/frame format and some information about certain files. A documentation of actual working of the compressor or decompressor would be greatly helpful for beginners like us. I really appreciate all the contributors for your excellent work.

Thank You!