handle nested

[sibelius]

• parse this on mongoose
• create a new GraphQLType to handle this
• create flowtype object for nested object

dimensions: {
      weight: {
        type: Number,
        min: 1,
        description: 'Product weight in grams',
      },
      length: {
        type: Number,
        min: 1,
        description: 'Product length in millimeters',
      },
      width: {
        type: Number,
        min: 1,
        description: 'Product width in millimeters',
      },
      height: {
        type: Number,
        min: 1,
        description: 'Product height in millimeters',
      },
    },