Added readme to package

Author: Ahmad Noman Musleh

src/OpenAPI.Net/OpenAPI.Net.csproj

@@ -14,8 +14,16 @@
     <Company>Spotware</Company>
     <Authors>Spotware</Authors>
     <RepositoryType>git</RepositoryType>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Include="..\..\README.md">
+      <Pack>True</Pack>
+      <PackagePath>\</PackagePath>
+    </None>
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="3.19.1" />
     <PackageReference Include="System.Reactive" Version="5.0.0" />