fleshed out GetVar, added Token stack collection, started printing module

pkg/shsh/var_table.go

@@ -13,5 +13,13 @@ var (
 // Library represents variables defined in inner scope
 // It is assumed library is ordered from innermost scope to outermost scope
 func GetVar(arg string, library []VarTable) *Token {
-    
+    for dict, scope := library {
+        val, ok := dict[arg]
+        if ok {
+            // TODO: maybe log which scope it was found in?
+            return val
+        }
+    }
+
+    return nil
 }