Add package description

Author: ddeboer

src/sidejob.app.src

@@ -1,5 +1,5 @@
 {application, sidejob, [
-    {description, ""},
+    {description, "sidejob is an Erlang library that implements a parallel, capacity-limited request pool. In sidejob, these pools are called resources. A resource is managed by multiple gen_server like processes which can be sent calls and casts using sidejob:call or sidejob:cast respectively."},
     {vsn, "git"},
     {registered, []},
     {applications, [kernel, stdlib]},