add main entry point and __main__ module

Author: chrissimpkins

src/run.py

@@ -0,0 +1,18 @@
+# This file is part of Slice.
+#
+#    Slice is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU General Public License as published by
+#    the Free Software Foundation, either version 3 of the License, or
+#    (at your option) any later version.
+#
+#    Slice is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with Slice.  If not, see <https://www.gnu.org/licenses/>.
+
+from slice.__main__ import main
+
+main()