remove unused usings

modules/docs/src/Volo.Docs.Domain/Volo/Docs/FileSystem/Documents/FileSystemDocumentStore.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.IO;
 using System.Security;
 using System.Threading.Tasks;

modules/docs/src/Volo.Docs.Domain/Volo/Docs/GitHub/Documents/GithubDocumentStore.cs

@@ -10,7 +10,6 @@ using Volo.Docs.GitHub.Projects;
 using Volo.Docs.Projects;
 using Newtonsoft.Json.Linq;
 using Octokit;
-using ProductHeaderValue = Octokit.ProductHeaderValue;
 using Project = Volo.Docs.Projects.Project;
 
 namespace Volo.Docs.GitHub.Documents

modules/docs/src/Volo.Docs.Domain/Volo/Docs/GitHub/Documents/GithubRepositoryManager.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Net.Http;
 using System.Net.Http.Headers;
-using System.Text;
 using System.Threading.Tasks;
 using Octokit;
 using Octokit.Internal;