Multiple past project crud

A multiple past projects management system has been done:

1. only admin can access to this page by clicking the button at the index page.

2. admin can view all pastprojects lists (or view by year/category, or view by searching the specific project in this page).

3. admin can add more projects in the system.

4. Using checkboxes, admin can select all or parts of projects to edit or delete in this page.