Update public API interface

Author: MaggieKimani1

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -1,7 +1,7 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Microsoft/OpenAPI.NET")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Microsoft.OpenApi.Readers.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100957cb48387b2a5f54f5ce39255f18f26d32a39990db27cf48737afc6bc62759ba996b8a2bfb675d4e39f3d06ecb55a178b1b4031dcb2a767e29977d88cce864a0d16bfc1b3bebb0edf9fe285f10fffc0a85f93d664fa05af07faa3aad2e545182dbf787e3fd32b56aca95df1a3c4e75dec164a3f1a4c653d971b01ffc39eb3c4")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Microsoft.OpenApi.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100957cb48387b2a5f54f5ce39255f18f26d32a39990db27cf48737afc6bc62759ba996b8a2bfb675d4e39f3d06ecb55a178b1b4031dcb2a767e29977d88cce864a0d16bfc1b3bebb0edf9fe285f10fffc0a85f93d664fa05af07faa3aad2e545182dbf787e3fd32b56aca95df1a3c4e75dec164a3f1a4c653d971b01ffc39eb3c4")]
-[assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName="")]
+[assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName=".NET Standard 2.0")]
 namespace Microsoft.OpenApi.Any
 {
     public enum AnyType
@@ -525,6 +525,7 @@ namespace Microsoft.OpenApi.Models
         public Microsoft.OpenApi.Models.OpenApiComponents Components { get; set; }
         public System.Collections.Generic.IDictionary<string, Microsoft.OpenApi.Interfaces.IOpenApiExtension> Extensions { get; set; }
         public Microsoft.OpenApi.Models.OpenApiExternalDocs ExternalDocs { get; set; }
+        public string HashCode { get; }
         public Microsoft.OpenApi.Models.OpenApiInfo Info { get; set; }
         public Microsoft.OpenApi.Models.OpenApiPaths Paths { get; set; }
         public System.Collections.Generic.IList<Microsoft.OpenApi.Models.OpenApiSecurityRequirement> SecurityRequirements { get; set; }
@@ -535,6 +536,7 @@ namespace Microsoft.OpenApi.Models
         public System.Collections.Generic.IEnumerable<Microsoft.OpenApi.Models.OpenApiError> ResolveReferences() { }
         public void SerializeAsV2(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }
         public void SerializeAsV3(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }
+        public static string GenerateHashValue(Microsoft.OpenApi.Models.OpenApiDocument doc) { }
     }
     public class OpenApiEncoding : Microsoft.OpenApi.Interfaces.IOpenApiElement, Microsoft.OpenApi.Interfaces.IOpenApiExtensible, Microsoft.OpenApi.Interfaces.IOpenApiSerializable
     {