init prisma migration readme

+# Migration `20200419160117-init`
+
+This migration has been generated by sdy at 4/19/2020, 4:01:17 PM.
+You can check out the [state of the schema](./schema.prisma) after the migration.
+
+## Database Steps
+
+```sql
+CREATE TABLE `chat_schema`.`User` (
+    `avatarUrl` varchar(191)   ,
+    `bio` varchar(191)   ,
+    `createdAt` datetime  DEFAULT CURRENT_TIMESTAMP ,
+    `email` varchar(191) NOT NULL  ,
+    `id` int NOT NULL  AUTO_INCREMENT,
+    `loginSecret` varchar(191)   ,
+    `name` varchar(191) NOT NULL  ,
+    `password` varchar(191) NOT NULL  ,
+    PRIMARY KEY (`id`)
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE TABLE `chat_schema`.`Room` (
+    `id` int NOT NULL  AUTO_INCREMENT,
+    PRIMARY KEY (`id`)
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE TABLE `chat_schema`.`Category` (
+    `id` int NOT NULL  AUTO_INCREMENT,
+    `name` varchar(191)  DEFAULT '' ,
+    PRIMARY KEY (`id`)
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE TABLE `chat_schema`.`Message` (
+    `id` int NOT NULL  AUTO_INCREMENT,
+    `senderId` int NOT NULL ,
+    `text` varchar(191)  DEFAULT '' ,
+    PRIMARY KEY (`id`)
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE TABLE `chat_schema`.`_RoomToUser` (
+    `A` int NOT NULL ,
+    `B` int NOT NULL 
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE TABLE `chat_schema`.`_CategoryToRoom` (
+    `A` int NOT NULL ,
+    `B` int NOT NULL 
+) 
+DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci
+
+CREATE UNIQUE INDEX `User.email` ON `chat_schema`.`User`(`email`)
+
+CREATE UNIQUE INDEX `_RoomToUser_AB_unique` ON `chat_schema`.`_RoomToUser`(`A`,`B`)
+
+CREATE  INDEX `_RoomToUser_B_index` ON `chat_schema`.`_RoomToUser`(`B`)
+
+CREATE UNIQUE INDEX `_CategoryToRoom_AB_unique` ON `chat_schema`.`_CategoryToRoom`(`A`,`B`)
+
+CREATE  INDEX `_CategoryToRoom_B_index` ON `chat_schema`.`_CategoryToRoom`(`B`)
+
+ALTER TABLE `chat_schema`.`Message` ADD FOREIGN KEY (`senderId`) REFERENCES `chat_schema`.`User`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
+
+ALTER TABLE `chat_schema`.`_RoomToUser` ADD FOREIGN KEY (`A`) REFERENCES `chat_schema`.`Room`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
+
+ALTER TABLE `chat_schema`.`_RoomToUser` ADD FOREIGN KEY (`B`) REFERENCES `chat_schema`.`User`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
+
+ALTER TABLE `chat_schema`.`_CategoryToRoom` ADD FOREIGN KEY (`A`) REFERENCES `chat_schema`.`Category`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
+
+ALTER TABLE `chat_schema`.`_CategoryToRoom` ADD FOREIGN KEY (`B`) REFERENCES `chat_schema`.`Room`(`id`) ON DELETE CASCADE ON UPDATE CASCADE
+
+DROP TABLE `chat_schema`.`_migration`;
+
+DROP TABLE `chat_schema`.`test`;
+```
+
+## Changes
+
+```diff
+diff --git schema.prisma schema.prisma
+migration ..20200419160117-init
+--- datamodel.dml
++++ datamodel.dml
+@@ -1,0 +1,41 @@
++generator client {
++  provider      = "prisma-client-js"
++  binaryTargets = ["native", "debian-openssl-1.1.x"]
++}
++
++datasource db {
++  provider = "mysql"
++  url      = env("DATABASE_URL")
++}
++
++model User {
++  id          Int       @default(autoincrement()) @id
++  avatarUrl   String?
++  email       String    @unique
++  password    String
++  name        String
++  loginSecret String?
++  bio         String?
++  rooms       Room[]    @relation(references: [id])
++  messages    Message[]
++  createdAt   DateTime? @default(now())
++}
++
++model Room {
++  id           Int        @default(autoincrement()) @id
++  participants User[]     @relation(references: [id])
++  categories   Category[] @relation(references: [id])
++}
++
++model Category {
++  id    Int     @default(autoincrement()) @id
++  name  String? @default("")
++  rooms Room[]  @relation(references: [id])
++}
++
++model Message {
++  id       Int     @default(autoincrement()) @id
++  text     String? @default("")
++  sender   User    @relation(fields: [senderId], references: [id])
++  senderId Int
++}
+```
+
+