Add README.md
Finish chapter 1.
Finish exercise 2.1
Finish exercise 2.5 to 2.10
Rename files due to 'require' need cross-platform path-filename
Finish Exercise 2.11
Finish Exercise 2.4
Finish Exercise 2.12
Move files into seperated folders.
Extract report-no-binding-found method to common file.
Finish Exercise 2.13
Add unit test for exercise 2.13
Use check-true or check-false instead of explicit check-eq? #t or #f.
Finish exercise 2.14
Finish exercise 2.15
Finish exercise 2.16, copied and modified from exercise 2.15