fix: public imports in Std

Author: Kha

src/Std.lean

@@ -4,12 +4,13 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Sebastian Ullrich
 -/
 module
+
 prelude
-import Std.Data
-import Std.Do
-import Std.Sat
-import Std.Sync
-import Std.Time
-import Std.Tactic
-import Std.Internal
-import Std.Net
+public import Std.Data
+public import Std.Do
+public import Std.Sat
+public import Std.Sync
+public import Std.Time
+public import Std.Tactic
+public import Std.Internal
+public import Std.Net