Adding Entity guides, flowcharts, better sample system. (#2054)

* initial

* Interaction glossary entry

* Sharded Interaction sample

* Renames into solution

* Debugging samples

* Modify target location for webhookclient

* Finalizing docs work, resolving docfx errors.

* Adding threaduser to user chart

* Add branch info to readme.

* Edits to user chart

* Resolve format for glossary entries

* Patch sln target

* Issue with file naming fixed

* Patch 1/x for builds

* Appending suggestions

docs/guides/entities/samples/unboxing.cs

@@ -0,0 +1,9 @@
+IUser user;
+
+// Here we use inline unboxing to make a call to its member (if available) only once.
+
+// Note that if the entity we're trying to cast to is null, this will throw a NullReferenceException.
+Console.WriteLine(((IGuildUser)user).Nickname);
+
+// In case you are certain the entity IS said member, you can also use unboxing to declare variables.
+IGuildUser guildUser = (IGuildUser)user;