schema.d.ts

export interface Coordinate {
    contacts: { [key: string]: Contact };
}

export interface Contact {
    birthday?: Date;
    emails:    string[];
    firstName: string;
    highScore: number;
    lastName?: string;
    phones:    PhoneNumber[];
    title?:    Title;
}

export interface PhoneNumber {
    /**
     * An optional label (e.g. "mobile")
     */
    label?: string;
    number: string;
}

export enum Title {
    MS = "Ms.",
    Mr = "Mr.",
    Mrs = "Mrs.",
    Prof = "Prof.",
}

schema.go

type Coordinate struct {
	Contacts map[string]Contact `json:"contacts"`
}

type Contact struct {
	Birthday  *string       `json:"birthday,omitempty"`
	Emails    []string      `json:"emails"`            
	FirstName string        `json:"firstName"`         
	HighScore float64       `json:"highScore"`         
	LastName  *string       `json:"lastName,omitempty"`
	Phones    []PhoneNumber `json:"phones"`            
	Title     *Title        `json:"title,omitempty"`   
}

type PhoneNumber struct {
	Label  *string `json:"label,omitempty"`// An optional label (e.g. "mobile")
	Number string  `json:"number"`         
}

type Title string
const (
	MS Title = "Ms."
	Mr Title = "Mr."
	Mrs Title = "Mrs."
	Prof Title = "Prof."
)

schema.json

{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "type": "object",
    "properties": {
        "contacts": {
            "type": "object",
            "additionalProperties": {
                "$ref": "#/definitions/Contact"
            }
        }
    },
    "required": [
        "contacts"
    ],
    "definitions": {
        "Contact": {
            "type": "object",
            "properties": {
                "firstName": {
                    "type": "string"
                },
                "lastName": {
                    "type": "string"
                },
                "birthday": {
                    "type": "string",
                    "format": "date-time"
                },
                "title": {
                    "enum": [
                        "Mr.",
                        "Mrs.",
                        "Ms.",
                        "Prof."
                    ],
                    "type": "string"
                },
                "emails": {
                    "type": "array",
                    "items": {
                        "type": "string"
                    }
                },
                "phones": {
                    "type": "array",
                    "items": {
                        "$ref": "#/definitions/PhoneNumber"
                    }
                },
                "highScore": {
                    "type": "integer"
                }
            },
            "required": [
                "emails",
                "firstName",
                "highScore",
                "phones"
            ]
        },
        "PhoneNumber": {
            "type": "object",
            "properties": {
                "number": {
                    "type": "string"
                },
                "label": {
                    "description": "An optional label (e.g. \"mobile\")",
                    "type": "string"
                }
            },
            "required": [
                "number"
            ]
        }
    }
}