Add README

README.md

+# Inventory Manager
+
+This software will help Mittelab guys in keeping their stuff ordered.
+
+## How is stuff organized?
+*Things* are organized in *containers*. Each thing can either have:
+
+- A parent Container
+- A Location ID
+
+In this way, we can either have a container (location ID, no parent
+container) or a thing (no location ID, parent container). For every
+*thing* there's a chain leading up to a *container* with a location ID.
+
+# Functionality
+Right now the app decodes a QR code, chen the user can add more metadata
+and finally save a *thing* in the database.