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/restentities.cs

@@ -0,0 +1,8 @@
+// RestUser entities expose the accent color and banner of a user.
+// This being one of the few use-cases for requesting a RestUser instead of depending on the Socket counterpart.
+public static EmbedBuilder WithUserColor(this EmbedBuilder builder, IUser user)
+{
+    var restUser = await _client.Rest.GetUserAsync(user.Id);
+    return builder.WithColor(restUser.AccentColor ?? Color.Blue);
+    // The accent color can still be null, so a check for this needs to be done to prevent an exception to be thrown.
+}