Update icon and link Readme in project file

Author: adityaoberai

templates/dotnet/icon.png

@@ -9,6 +9,7 @@
       {{sdk.shortDescription}}
     </Description>
     <PackageIcon>icon.png</PackageIcon>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
     <PackageLicenseExpression>{{spec.licenseName}}</PackageLicenseExpression>
     <PackageProjectUrl>{{sdk.gitURL}}</PackageProjectUrl>
     <RepositoryType>git</RepositoryType>
@@ -22,6 +23,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
     <None Include="..\..\icon.png" Pack="true" PackagePath="$(PackageIcon)"/>
+	  <None Include="..\..\README.md" Pack="true" PackagePath="$(PackageReadmeFile)"/>
   </ItemGroup>
 
 </Project>