Update the ASP.NET Core 3.1-to-5.0 migration guide for Preview 3 (#18037)

Author: scottaddie

aspnetcore/migration/31-to-50.md

@@ -4,7 +4,7 @@ author: scottaddie
 description: Learn how to migrate an ASP.NET Core 3.1 project to ASP.NET Core 5.0.
 ms.author: scaddie
 ms.custom: mvc
-ms.date: 04/02/2020
+ms.date: 04/28/2020
 uid: migration/31-to-50
 ---
 # Migrate from ASP.NET Core 3.1 to 5.0
@@ -40,21 +40,21 @@ If you rely upon a [global.json](/dotnet/core/tools/global-json) file to target
 {
   "sdk": {
 -    "version": "3.1.200"
-+    "version": "5.0.100-preview.2.20176.6"
++    "version": "5.0.100-preview.3.20216.6"
   }
 }
 ```
 
 ## Update the target framework
 
-In the project file, update the [Target Framework Moniker (TFM)](/dotnet/standard/frameworks) to `netcoreapp5.0`:
+In the project file, update the [Target Framework Moniker (TFM)](/dotnet/standard/frameworks) to `net5.0`:
 
 ```diff
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
 -    <TargetFramework>netcoreapp3.1</TargetFramework>
-+    <TargetFramework>netcoreapp5.0</TargetFramework>
++    <TargetFramework>net5.0</TargetFramework>
   </PropertyGroup>
 
 </Project>
@@ -68,14 +68,14 @@ In the project file, update each `Microsoft.AspNetCore.*` and `Microsoft.Extensi
 <ItemGroup>
 -    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="3.1.2" />
 -    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="3.1.2" />
-+    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="5.0.0-preview.2.20167.3" />
-+    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="5.0.0-preview.2.20160.3" />
++    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="5.0.0-preview.3.20215.14" />
++    <PackageReference Include="Microsoft.Extensions.Caching.Abstractions" Version="5.0.0-preview.3.20215.2" />
 </ItemGroup>
 ```
 
 ## Update Docker images
 
-For apps using Docker, use a base image that includes ASP.NET Core 5.0. For example:
+For apps using Docker, use a base image that includes the ASP.NET Core 5.0 runtime. For example:
 
 ```bash
 docker pull mcr.microsoft.com/dotnet/core/aspnet:5.0