Update README (microsoft#60)

* Update README

* Address comments

src/Microsoft.Build.Sql/README.md

@@ -6,6 +6,8 @@
 ## Current Status
 This project is in its early stages and we are currently building tests for different functionality. Contributors welcome, please feel free to share feedback or PRs.
 
+The latest alpha release can be found on [Nuget.org](https://www.nuget.org/packages/Microsoft.Build.Sql/).
+
 ## Using this SDK
 
 ### Changes to .sqlproj file
@@ -28,8 +30,41 @@ The database project can be built in SSDT (tested in Visual Studio 2017+) as is.
 ```
 dotnet build /p:NetCoreBuild=true
 ```
-In Visual Studio 2019 (or newer), .NET Core targets can be used by default. Add this property to the sqlproj:
+In Visual Studio, .NET Core targets can be used by default. Add this property to the sqlproj:
 ```xml
 <NetCoreBuild>True</NetCoreBuild>
 ```
-and the project can be built directly in VS 2019 or `dotnet build` from command line.
+and the project can be built directly in Visual Studio or `dotnet build` from command line.
+
+## Resolving build errors/warnings
+Depending on if your database project originated from SSDT, [Azure Data Studio](https://aka.ms/azuredatastudio-sqlprojects), or VS Code, you may encounter build errors or warnings like these:
+```
+error MSB4019: The imported project "C:\Program Files\dotnet\sdk\6.0.100-rc.1.21458.32\Microsoft\VisualStudio\v11.0\SSDT\Microsoft.Data.Tools.Schema.SqlTasks.targets" was not found. Confirm that the expression in the Import declaration "C:\Program Files\dotnet\sdk\6.0.100-rc.1.21458.32\\Microsoft\VisualStudio\v11.0\SSDT\Microsoft.Data.Tools.Schema.SqlTasks.targets" is correct, and that the file exists on disk.
+```
+or
+```
+warning MSB4011: "C:\Program Files\dotnet\sdk\6.0.100-rc.1.21458.32\Current\Microsoft.Common.props" cannot be imported again. It was already imported at "C:\test\Database1\Database1.sqlproj (4,3)". This is most likely a build authoring error. This subsequent import will be ignored.
+```
+To resolve these errors/warnings, remove any default `<Import>` statements from the project file that reference `Microsoft.Data.Tools.Schema.SqlTasks.targets` or `Microsoft.Common.props`.
+
+### Example statements to remove
+```xml
+<Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+```
+```xml
+<Import Condition="..." Project="...\Microsoft.Data.Tools.Schema.SqlTasks.targets"/>
+```
+
+* Note: This only applies to the auto-generated statements that come from SSDT or ADS. Please keep any custom `<Import>` targets that you may have added to the project file.
+
+## (Optional) Simplifying the project file
+A major advantage of SDK-style projects is a lot of default properties can be defined in the SDK, which means the project file itself can be dramatically simplified.
+
+In addition to the `<Import>` statements that are no longer needed, properties such as build configuration and platform can be removed as well. See the [sample sqlproj file](../../samples/SdkStyleDatabaseProject/sample.sqlproj) for the minimum properties that are needed to build a DACPAC.
+
+### Default SQL files included in build
+The SDK specifies a default globbing pattern to include `**/*.sql` from the project root, so all the explicit `<Build Include="filename.sql"/>` can be removed.
+* .sql files that do not fall under the default globbing pattern still need to be included explicitly.
+* Pre/post-deployment scripts that are specified by the `<PreDeploy>` or `<PostDeploy>` tags are automatically excluded from build.
+* To manually exclude a .sql file from the project, add `<Build Remove="filename.sql"/>` to the project file.
+* Even though build will honor the default globbing pattern, .sql files that are not included explicitly will not be displayed inside Solution Explorer in SSDT. Support for this will be added in a future release of SSDT.