Recreated LEGO Bricks Widget README. (#4792)

* Recreated LEGO Bricks Widget README

* Moved LEGO Bricks Widget section from main README to a new file as requested

* Restored LEGO Bricks Widget section in guide/README.md as requested

---------

Co-authored-by: Roshni Pradeep Naktode <[email protected]>

Author: roshninaktode