Snapshot 3

Complete:
- Create the Home page for the website
- Collecting the picture's material that we are going to use in the future
- Build a Maven project
- All the team member well set up the environment
(Updated at 2021/3/22):
- build database ebuy(t_category, t_product, t_order, t_user)
- Finished UserMapper
- Finished CategoryMapper
- Finished ProductMapper
- Finished Order class with the functions that can check status of order, set the order number、order price and order ID
- test Mapper and database
Plan:
-Finish index and user page (next week)
-Finish controller and some connect page with controller(next 2 week)
Concern:
- Currently null