[init] Fix signal and timer entries, capitalize them since they are classes.

init.lua

@@ -17,8 +17,9 @@ return {
     meta = require(BASE..'meta'),
     rect = require(BASE..'rect'),
     shadowtext = require(BASE..'shadowtext'),
-    signal = require(BASE..'signal'),
     strings = require(BASE..'strings'),
-    timer = require(BASE..'timer'),
-    vec = require(BASE..'vec')
+    vec = require(BASE..'vec'),
+
+    Signal = require(BASE..'signal'),
+    Timer = require(BASE..'timer')
 }