Add a simple, direct way to use BAT, without requiring to setup a venv etc.

Allows to use `python3 path/to/cli.py my args` just from source code,
without requiring to set up a whole venv for that. Much simpler when
only 'regular' debuging in code logic itself is needed.

README.md

@@ -8,6 +8,15 @@ Blender Asset Tracer, a.k.a. BAT🦇, is the replacement of
 
 Development is driven by choices explained in [T54125](https://developer.blender.org/T54125).
 
+## Basic access to command line operations
+
+The `cli.py` wrapper at the root of the project can be used to directly access the command line
+tools, without requiring any setup involving `venv` and so on:
+
+```
+python3 path/to/repo/cli.py list path/to/blendfile.blend
+```
+
 ## Setting up development environment
 
 ```

cli.py

@@ -0,0 +1,29 @@
+# ##### BEGIN GPL LICENSE BLOCK #####
+#
+#  This program 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 2
+#  of the License, or (at your option) any later version.
+#
+#  This program 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 this program; if not, write to the Free Software Foundation,
+#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+#
+#  Copyright (C) 2014-2018 Blender Foundation
+#
+# ##### END GPL LICENSE BLOCK #####
+
+# <pep8 compliant>
+
+
+import blender_asset_tracer.cli
+
+if __name__ == "__main__":
+    print("\n\n *** Running {} *** \n".format(__file__))
+    blender_asset_tracer.cli.cli_main()
+