Create initial version of server

Just a very simple TCP echo server to get started with.

server/src/study_system_server_app.erl

@@ -0,0 +1,14 @@
+% Copyright (c) Camden Dixie O'Brien
+% SPDX-License-Identifier: AGPL-3.0-only
+
+-module(study_system_server_app).
+-behaviour(application).
+
+-export([start/2, stop/1]).
+
+start(_StartType, _StartArgs) ->
+	Port = application:get_env(study_system_server, port, 12888),
+	proto_sup:start_link(Port).
+
+stop(_State) ->
+	ok.