fix(env): replace mysql url template with postgres one

Author: Alen

.env.example

@@ -21,7 +21,7 @@ AUTH_DISCORD_SECRET=""
 
 # Prisma
 # https://www.prisma.io/docs/reference/database-reference/connection-urls#env
-DATABASE_URL="mysql://root:password@localhost:3306/vault"
-DATABASE_DIRECT_URL="mysql://root:password@localhost:3306/vault"
+DATABASE_URL="postgres://postgres:password@localhost:3306/vault"
+DATABASE_DIRECT_URL="postgres://postgres:password@localhost:3306/vault"
 
 ENABLE_USER_WHITELIST=