Document fixed-size numeric field types

[TarantoolBot]

Product: Tarantool
Since: 3.1
Root document: https://www.tarantool.io/en/doc/latest/concepts/data_model/value_store/#field-type-details

Fixed-size field types

Tarantool supports the following fixed-size numeric field types:

• uint8: integer in range [0 .. 255]
• int8: integer in range [-128 .. 127]
• uint16: integer in range [0 .. 65,535]
• int16: integer in range [-32,768 .. 32,767]
• uint32: integer in range [0 .. 4,294,967,295]
• int32: integer in range [-2,147,483,648 .. 2,147,483,647]
• uint64: integer in range [0 .. 18,446,744,073,709,551,615]
• int64: integer in range [-9,223,372,036,854,775,808 ..
  9,223,372,036,854,775,807]
• float32: 32-bit floating point number
• float64: 64-bit floating point number

These types don't affect how data is stored in Tarantool's memtx or vinyl
engines but they enforce the limits when a tuple is inserted or updated.
Requested by @Gumix in tarantool/tarantool@2e0f9a3.