UI/UX improvements for new tasks and navigation. Fixes.

...rosetta/core_app/management/commands/core_app_populate.py

...code/rosetta/core_app/templates/components/container.html

...es/webapp/code/rosetta/core_app/templates/containers.html

...s/webapp/code/rosetta/core_app/templates/create_task.html

services/webapp/code/rosetta/core_app/templates/main.html

services/webapp/code/rosetta/core_app/templates/tasks.html

services/webapp/code/rosetta/core_app/views.py