feat(prisma): add review "written at" date field

This patch adds a new `date` field to the `Review` object. This date
field will be `NULL` for consumer reviews (as the written at date for
consumer reviews will simply be createdAt/updatedAt). For critic
reviews, this is a separate field as most of the time, the date when the
critic review was originally written will be different from the date I
imported it.

prisma/migrations/20230725043335_add_review_written_at_date/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "Review" ADD COLUMN     "date" TIMESTAMP(3);

prisma/schema.prisma

@@ -798,6 +798,14 @@ model Review {
   // The review article URL (if it was posted online e.g. on Vogue).
   url String? @unique
 
+  // The date when the review article was originally written (if known).
+  // 
+  // This will be NULL for consumer reviews (as this would be redundant with the
+  // database createdAt field for consumer reviews). For critic reviews, the
+  // date when the review was originally written and the time when I imported it
+  // will often be different (which is why this field exists separately).
+  date DateTime?
+
   // Each user can only submit one review per show. This may be different for
   // critic reviews, but, for now, I've yet to encounter the same journalist
   // publishing two different reviews for the same show. If that does happen, I