Updated readme and added new sample project

samples/ReadmeSample/ApplicationDbContext.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Cryptography.X509Certificates;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projections.Extensions;
+using Microsoft.EntityFrameworkCore;
+using ReadmeSample.Entities;
+
+namespace ReadmeSample
+{
+    public class ApplicationDbContext : DbContext
+    {
+        public DbSet<User> Users { get; set; }
+        public DbSet<Product> Products { get; set; }
+        public DbSet<Order> Orders { get; set; }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Database=ReadmeSample;Trusted_Connection=True");
+            optionsBuilder.UseProjections();
+        }
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            modelBuilder.Entity<OrderItem>().HasKey(x => new { x.OrderId, x.ProductId });
+        }
+
+    }
+}

samples/ReadmeSample/Entities/Order.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projections;
+
+namespace ReadmeSample.Entities
+{
+    public class Order
+    {
+        public int Id { get; set; }
+        public int UserId { get; set; }
+        public DateTime CreatedDate { get; set; }
+
+        public decimal TaxRate { get; set; }
+
+        public User User { get; set; }
+        public ICollection<OrderItem> Items { get; set; }
+
+        [Projectable] public decimal Subtotal => Items.Sum(item => item.Product.ListPrice * item.Quantity);
+        [Projectable] public decimal Tax => Subtotal * TaxRate;
+        [Projectable] public decimal GrandTotal => Subtotal + Tax;
+    }
+}

samples/ReadmeSample/Entities/OrderItem.cs

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+namespace ReadmeSample.Entities
+{
+    public class OrderItem
+    {
+        public int OrderId { get; set; }
+        public int ProductId { get; set; }
+        public int Quantity { get; set; }
+
+        public Order Order { get; set; }
+        public Product Product { get; set; }
+    }
+}

samples/ReadmeSample/Entities/Product.cs

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+namespace ReadmeSample.Entities
+{
+    public class Product
+    {
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+
+        public decimal ListPrice { get; set; }
+    }
+}

samples/ReadmeSample/Entities/User.cs

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+using System.Collections;
+using System.Collections.Generic;
+
+namespace ReadmeSample.Entities
+{
+    public class User
+    {
+        public int Id { get; set; }
+
+        public string UserName { get; set; }
+
+        public string EmailAddress { get; set; }
+
+        public ICollection<Order> Orders { get; set; }
+    }
+}

samples/ReadmeSample/Extensions/UserExtensions.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using EntityFrameworkCore.Projections;
+using ReadmeSample.Entities;
+
+namespace ReadmeSample.Extensions
+{
+    public static class UserExtensions
+    {
+        [Projectable]
+        public static Order GetMostRecentOrderForUser(this User user, DateTime? cutoffDate)
+            => user.Orders.Where(x => x.CreatedDate >= cutoffDate).OrderByDescending(x => x.CreatedDate).FirstOrDefault();
+    }
+}

samples/ReadmeSample/Program.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Microsoft.EntityFrameworkCore;
+using ReadmeSample.Entities;
+using ReadmeSample.Extensions;
+
+namespace ReadmeSample
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            using var dbContext = new ApplicationDbContext();
+
+            // recreate database
+            dbContext.Database.EnsureDeleted();
+            dbContext.Database.EnsureCreated();
+
+            // Populate with seed data
+            var sampleUser = new User { UserName = "Jon", EmailAddress = "jon@doe.com" };
+            var sampleProduct = new Product { Name = "Blue Pen", ListPrice = 1.5m };
+            var sampleOrder = new Order {
+                User = sampleUser,
+                TaxRate = .19m,
+                CreatedDate = DateTime.UtcNow,
+                Items = new List<OrderItem> {
+                    new OrderItem { Product = sampleProduct, Quantity = 5  }
+                }
+            };
+
+            dbContext.AddRange(sampleUser, sampleProduct, sampleOrder);
+            dbContext.SaveChanges();
+
+            // Lets try a query!
+            var query = dbContext.Users
+                .Where(x => x.UserName == "Jon")
+                .Select(x => new {
+                    x.GetMostRecentOrderForUser(DateTime.UtcNow.AddDays(-30)).GrandTotal
+                });
+
+            var result = query.First();
+
+            Console.WriteLine($"Jons latest order had a grant total of {result.GrandTotal}");
+            Console.WriteLine($"The following query was used to fetch the results:");
+            Console.WriteLine(query.ToQueryString());
+        }
+    }
+}

samples/ReadmeSample/ReadmeSample.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net5.0</TargetFramework>
+    <Nullable>disable</Nullable>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+    <CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)Generated</CompilerGeneratedFilesOutputPath>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="5.0.6" />
+    <PackageReference Include="Microsoft.Extensions.Logging" Version="5.0.0" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="5.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\EntityFrameworkCore.Projections.Generator\EntityFrameworkCore.Projections.Generator.csproj" OutputItemType="Analyzer" ReferenceOutputAssembly="false" />
+    <ProjectReference Include="..\..\src\EntityFrameworkCore.Projections\EntityFrameworkCore.Projections.csproj" />
+  </ItemGroup>
+
+</Project>