Restructuring a blog to a portfolio in Sanity and 11ty

import {format} from 'date-fns'

export default {
  name: 'project',
  type: 'document',
  title: 'Project',
  fields: [
    {
      name: 'title',
      type: 'string',
      title: 'Title',
      description: 'Titles should be catchy, descriptive, and not too long'
    },
    {
      name: 'slug',
      type: 'slug',
      title: 'Slug',
      description: 'Some frontends will require a slug to be set to be able to show the post',
      options: {
        source: 'title',
        maxLength: 96
      }
    },
    {
      //Change this field from publishedAt to completionDate. Since you're not scheduling a post any more, it can become a date instead of a dateTime
      name: 'completionDate',
      type: 'date',
      title: 'Completion Date',
    },
    {
      name: 'mainImage',
      type: 'mainImage',
      title: 'Main image'
    },
    {
      //If this is a personal portfolio, this field can be removed since the author will always be you. 
      name: 'authors',
      title: 'Authors',
      type: 'array',
      of: [
        {
          type: 'authorReference'
        }
      ]
    },
    {
      name: 'categories',
      type: 'array',
      title: 'Categories',
      of: [
        {
          type: 'reference',
          to: {
            type: 'category'
          }
        }
      ]
    },
    {
      name: 'description',
      type: 'bodyPortableText',
      title: 'Descriptionm'
    }
  ],
  orderings: [
    {
      name: 'completionDateAsc',
      title: 'Completion date new–>old',
      by: [
        {
          field: 'completionDate',
          direction: 'asc'
        },
        {
          field: 'title',
          direction: 'asc'
        }
      ]
    },
    {
      name: 'completionDateDesc',
      title: 'Completion date old->new',
      by: [
        {
          field: 'completionDate',
          direction: 'desc'
        },
        {
          field: 'title',
          direction: 'asc'
        }
      ]
    }
  ],
  preview: {
    select: {
      title: 'title',
      creationDate: 'creationDate',
      slug: 'slug',
      media: 'mainImage'
    },
    prepare ({title = 'No title', completionDate, slug = {}, media}) {
      const dateSegment = format(completionDate, 'YYYY/MM')
      const path = `/${dateSegment}/${slug.current}/`
      return {
        title,
        media,
        subtitle: completionDate ? path : 'Missing completion date'
      }
    }
  }
}