Fix a defect that the same explaination is applied in any cases.
Finished the functionality of Land Du Ke Wen.
Apply new page design from Sam.
Integrate ZhongDianXiangJie into index.html

- Integrate ZhongDianXiangJie into index.html
- Remove old jQuery lib and redundant css file.
fine-tune UI of ZhongDianXiangJie.
Integrate DanCiJuXing to index.html
完成"朗读全文"部分

Integrate "Lang Du Quan Wen" to index.html.
Show practice list onto page.