Telegram bot API types

• Types must be data classes
• Types must be serializable
• Class names must correspond to https://core.telegram.org/bots/api
• Property names must correspond to https://core.telegram.org/bots/api
• Class properties and fields in https://core.telegram.org/bots/api must match
• Optional fields from https://core.telegram.org/bots/api must be nullable with default null value
• Fully documented
• Serialization / deserialization must be tested
• KDocs must correspond to https://core.telegram.org/bots/api
• Tests
• Coverage