add a little readme

README.md

@@ -1,2 +1,16 @@
-# outline-rs
+# Outline-rs
 
+lightweight relational database-backed personal knowledge management outliner
+
+*Very* under construction!
+
+## Motivation
+
+Two PKM apps I've tried use Electron frontends, and I want a library that can
+back different frontends depending on the environment. I have been
+using a low-power ARM laptop recently and I can't be running a whole browser
+engine just to take notes.
+Also, containing all note data in a database will allow for extending with
+sync servers as a first-class experience rather than an afterthought.
+
+Using this as a project to learn rust as I go.