[8pt] Getting started with fibers

[NickVolynkin]

Fiber how-to

Follow-up to #1448

Product: Tarantool
Since:
Audience/target: Lua devs
Root document: https://www.tarantool.io/en/doc/latest/reference/reference_lua/fiber/
https://www.tarantool.io/en/doc/latest/book/box/atomic/#cooperative-multitasking
SME: @Mons
Peer reviewer: @ documentarian name

Details

• Take content from training videos
• Reuse samples from golang

Definition of done