TDB (iproto): create and update the Reference section

[xuniq]

Epic: #4002
Product: Tarantool DB
Root document:

• to be created: https://github.com/tarantool/tarantooldb/blob/master/doc/reference/

SME: @ a1div0 @ Galiev-Ruslan

Details

Section structure

• Список технологических ролей в TDB.
• Справочник по конфигурации
• Справочник по встроенным модулям (dictionary, tracing)

Definition of done

• proofread the section: language, style, formatting
• reduce the number of cross-links, add and update other links if needed
• add intro description to the Reference page
• add overview texts to other pages if needed:
  - [ ] Технологические роли в TDB

[xuniq]

Merged in scope of https://github.com/tarantool/tarantooldb/pull/304