Add XML docs to nuget package

Author: Gonkers

ScryfallApi.sln

@@ -11,6 +11,11 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ScryfallApi.WebSample", "sa
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ScryfallApi.NetFxExample", "samples\ScryfallApi.NetFxExample\ScryfallApi.NetFxExample.csproj", "{9EE20F37-E50E-4395-A37D-979AD38D995A}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{F938EC12-7230-41F9-A93F-44E9D4DCAF02}"
+	ProjectSection(SolutionItems) = preProject
+		README.md = README.md
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU

src/ScryfallApi.Client/ScryfallApi.Client.csproj

@@ -2,14 +2,15 @@
 
   <PropertyGroup>
     <TargetFrameworks>net461;netstandard2.0</TargetFrameworks>
-  <PackageId>ScryfallAPI.Client</PackageId>
+    <PackageId>ScryfallAPI.Client</PackageId>
     <Version>2.0.0</Version>
     <Authors>Gonkers</Authors>
     <Company />
     <Description>.NET client library for accessing the scryfall.com API</Description>
     <PackageProjectUrl>https://github.com/Gonkers/Scryfall-API-Client</PackageProjectUrl>
     <RepositoryUrl>https://github.com/Gonkers/Scryfall-API-Client</RepositoryUrl>
-  <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <PackageTags>scryfall scryfall-api</PackageTags>
     <LangVersion>latest</LangVersion>
   </PropertyGroup>