Pre-Wiki Update (#285)

This PR has been opened to finally update Octobot's Wiki.

Current changes summary:
- correct minor spelling issues in some command descriptions
- /about: add Octobot's Wiki button

---------

Signed-off-by: mctaylors <cantsendmails@mctaylors.ru>

src/BuildInfo.cs

@@ -6,6 +6,8 @@ public static class BuildInfo
 
     public static string IssuesUrl => $"{RepositoryUrl}/issues";
 
+    public static string WikiUrl => $"{RepositoryUrl}/wiki";
+
     private static string Commit => ThisAssembly.Git.Commit;
 
     private static string Branch => ThisAssembly.Git.Branch;