feat：添加自述文件

Author: wangpengxpy

src/EFCore.KingbaseES/EFCore.KingbaseES.csproj

@@ -16,6 +16,8 @@
     <AssemblyOriginatorKeyFile>..\..\Npgsql.snk</AssemblyOriginatorKeyFile>
     <PackageIcon>icon.png</PackageIcon>
     <PackageLicenseExpression>PostgreSQL</PackageLicenseExpression>
+    <PackageReadmeFile>README.md</PackageReadmeFile>
+    <PackageProjectUrl>https://github.com/dotnetcore/EntityFrameworkCore.KingbaseES</PackageProjectUrl>
     <!-- Precompiled query is experimental -->
   </PropertyGroup>
 
@@ -36,6 +38,10 @@
       <Pack>True</Pack>
       <PackagePath>\</PackagePath>
     </None>
+    <None Include="..\..\README.md">
+      <Pack>True</Pack>
+      <PackagePath>\</PackagePath>
+    </None>
 
     <None Update="Properties\KdbndpStrings.Designer.tt">
       <Generator>TextTemplatingFileGenerator</Generator>