[Chapter 4] Fixed problem 4.27 (c)

[Chapter 5] Fixed exercises 5.x

Fixed a typo in problem 4.14

Removed extra back slash in problem 4.14

Update README.md

Update README.md

Delete Solutions to Chapter 1 The Learning Problem.html

Delete Solutions to Chapter 1 Problems.ipynb

Delete Solutions to Chapter 1 Exercises.ipynb

Update README.md

Added appendix C

Mark problem 9.11 as TODO

Added exercises B.1-B.7

Added appendixes B, C

Added problem 9.11