[Epic] ATE documentation

[xuniq]

Related dev. issue(s): https://jira.vk.team/browse/TNTP-1108
Product: ATE
Root document: https://www.tarantool.io/en/devops/latest/
SME: @ opomuc @ lastoCHka42

Details

1-й приоритет:

• ATE: describe ATE variables #5294
• ATE: update info about TDB and its playbooks in the ATE docs #5299
• [2.x] TDB (IPROTO): update TDB inventory files #4969
• [2.x] TDB (IPROTO): check and update info about migrations in the ATE docs #4971
• ATE: update TDB install guide in TDB docs #5308
• ATE: check Tarantool 3.x section #5301
• ATE: update playbooks' description #5295

2-й приоритет:

• ATE: proofread changelog and publish it on Tarantool website #5292
• ATE: describe file structure after deploy #5296
• ATE: update TDB RESP description #5297
• ATE: update TDB (RESP) naming in the ATE docs #4643
• ATE: Использование start/stop/restart при деплое с помощью root #5298
• ATE: update TCF deploy section (TDB 2.x + TCF) #5273
• ATE: build docs in PDF #5307
• ATE: describe eval_schema_update.yml playbook #5399