Ensure trailing slash in <SourceRoot> (#1327)

Ensure trailing slash in <SourceRoot>

Author: hallipr

DeterministicBuild.targets

@@ -9,7 +9,7 @@ https://github.com/dotnet/sourcelink/issues/572 -->
     <EmbeddedFiles Include="$(GeneratedAssemblyInfoFile)"/>
   </ItemGroup>
   <ItemGroup>
-    <SourceRoot Include="$(NuGetPackageRoot)" />
+    <SourceRoot Include="$([MSBuild]::EnsureTrailingSlash($(NuGetPackageRoot)))" Condition="'$(NuGetPackageRoot)' != ''" />
   </ItemGroup>
 
   <Target Name="CoverletGetPathMap"

Documentation/DeterministicBuild.md

@@ -47,7 +47,7 @@ https://github.com/dotnet/sourcelink/issues/572 -->
     <EmbeddedFiles Include="$(GeneratedAssemblyInfoFile)"/>
   </ItemGroup>
   <ItemGroup>
-    <SourceRoot Include="$(NuGetPackageRoot)" />
+    <SourceRoot Include="$([MSBuild]::EnsureTrailingSlash($(NuGetPackageRoot)))" Condition="'$(NuGetPackageRoot)' != ''" />
   </ItemGroup>
 
   <Target Name="CoverletGetPathMap"

Documentation/Examples/MSBuild/DeterministicBuild/DeterministicBuild.targets

@@ -9,7 +9,7 @@ https://github.com/dotnet/sourcelink/issues/572 -->
     <EmbeddedFiles Include="$(GeneratedAssemblyInfoFile)"/>
   </ItemGroup>
   <ItemGroup>
-    <SourceRoot Include="$(NuGetPackageRoot)" />
+    <SourceRoot Include="$([MSBuild]::EnsureTrailingSlash($(NuGetPackageRoot)))" Condition="'$(NuGetPackageRoot)' != ''" />
   </ItemGroup>
 
   <Target Name="CoverletGetPathMap"

Documentation/Examples/VSTest/DeterministicBuild/DeterministicBuild.targets

@@ -9,7 +9,7 @@ https://github.com/dotnet/sourcelink/issues/572 -->
     <EmbeddedFiles Include="$(GeneratedAssemblyInfoFile)"/>
   </ItemGroup>
   <ItemGroup>
-    <SourceRoot Include="$(NuGetPackageRoot)" />
+    <SourceRoot Include="$([MSBuild]::EnsureTrailingSlash($(NuGetPackageRoot)))" Condition="'$(NuGetPackageRoot)' != ''" />
   </ItemGroup>
 
   <Target Name="CoverletGetPathMap"