Add tiny README

README.md

+ai3/tools/live
+===
+
+A toolkit to manage a RTMP/HLS-based video streaming service, with few
+streams and many listeners. The toolkit will autoscale a pool of
+reverse HTTP proxies, which will relay content from a single streaming
+server which takes care of the RTMP-to-HLS conversion.
+
+## Auto-scaling
+
+Auto-scaling works by managing a pool of cloud instances via an
+API. Instances are scaled up and down based on the global utilization
+of the entire pool (compared to thresholds, with hystheresis).
+
+Instances report their utilization to a centralized service. This
+service:
+
+* serves DNS requests for specific instances
+* serves HTTP requests by redirecting clients to a specific instance
+  based on the output of load-balancing algorithm
+
+