add sql course (#4897)
* add sql course
* add react free course
* Revert "add react free course"
This reverts commit 3607c3b935d508d55a3df69405ad28d1c8e8f3d1.
* Update free-courses-vi.md
Co-authored-by: Seth <seth@elypia.org>
Co-authored-by: Seth <seth@elypia.org>