Add panels on the starter page

Use sphinx-panels https://sphinx-panels.readthedocs.io/en/latest/

• 1st-type panels at https://www.tarantool.io/en/doc/latest/
• 2nd-type panels at https://www.tarantool.io/ru/doc/latest/getting_started/
• 3st-type at https://www.tarantool.io/en/doc/latest/reference/reference_lua/box_space/

Reviewer: @NataliaPlatova @Katedraw