1. Adding other files to index
2. Some fixes to chapter 00, 01, 02, and 03
3. Partial translation of Chapter 04 (80%)
4. Partial translation of Chapter 15 (60%)
Finalize translation of Chapter 04 (100%).
A few stylistic fixes and typos in Chapters 01 and 02
Full translation of Chapter 05. Several fixes to the previouse chapters