Update collector docs (#522)

update docs

Author: MarcoRossignoli

Documentation/VSTestIntegration.md

@@ -1,30 +1,22 @@
 # Coverlet Integration with VSTest
 
-## Motivation
-
-The cross platform solution for Code Coverage generation for .NET Core projects (in a consistent manner).
-The asks for Code Coverage support for .NET Core on Linux is the most commented issue on vstest repo:
-https://github.com/Microsoft/vstest/issues/981#issuecomment-320311552
-
-## Summary
-
-What would integrating Coverlet with Microsoft Test Platform mean:
-
-1. Coverlet based coverage solution is available as a data collector that does the instrumentation of the necessary modules before test execution and appropriate restore after.
-2. Authoring - When new test projects are created (dotnet mstest), references to the data collector package are added by default. This reduces adoption friction for customers.
-3. Test execution - Today Coverlet is invoked as a msbuild target and as such only works with dotnet test (and requires a csproj). With the data collector becoming available, coverage can also be collected when tests are run on built binaries (dotnet vstest)
-
-## Proposed Solution
-
-### Scenarios to support
-
-The following table summarizes the support that needs to be added for a seamless code coverage collection for .NET Core on both Linux and Windows platforms:
 
 | Entry point | How will code coverage be enabled? | Syntax                                                               |
 |-------------|------------------------------------|----------------------------------------------------------------------|
 |dotnet test CLI              | Through a switch to condition data collection | `dotnet test --collect:"XPlat Code Coverage"`   |
 |dotnet vstest CLI            | Through a switch to condition data collection | `dotnet vstest --collect:"XPlat Code Coverage"` |
 
+NB. If you're using `dotnet vstest` you MUST `publish` your test project before i.e.
+```bash
+C:\project
+dotnet publish
+...
+  vstest -> C:\project\bin\Debug\netcoreapp3.0\testdll.dll
+  vstest -> C:\project\bin\Debug\netcoreapp3.0\publish\
+...
+dotnet vstest C:\project\bin\Debug\netcoreapp3.0\publish\testdll.dll --collect:"XPlat Code Coverage"
+```
+
 ### Coverlet Options Supported with VSTest
 
 #### Default
@@ -75,11 +67,6 @@ This runsettings file can easily be provided using command line option as given
 
 2. `dotnet vstest --settings coverletArgs.runsettings`
 
-
-#### Scope of Enhancement
-
-Currently, advanced options are supported via runsettings. Providing support through additional command line arguments in vstest can be taken up separately.
-
 ## Implementation Details
 
 The proposed solution is implemented with the help of [datacollectors](https://github.com/Microsoft/vstest-docs/blob/master/docs/extensions/datacollector.md).