docs: add Docker-based quick start section
# Oak Development
+- [Quick Start](#quick-start)
- [Meta-Advice](#meta-advice)
- [Prerequisites](#prerequisites)
- [Run Example Application](#run-example-application)
- [Run Runtime Server](#run-runtime-server)
- [Run Example Client](#run-example-client)
+## Quick Start
+
+To build and run one of the Oak example applications under Docker, run:
+
+```bash
+./scripts/docker_pull # retrieve cached Docker image for faster builds
+./scripts/docker_run ./scripts/run_example -e hello_world
+```
+
+This should build the Runtime, an Oak Application and a client for the
+Application, then run them all, with log output ending something like the
+following:
+
+```log
+2020-05-11 17:24:18,770 INFO [oak_runtime::runtime] stopping runtime instance
+2020-05-11 17:24:18,770 DEBUG [oak_runtime::runtime] waking waiters on NodeId(0) handle 11172775277784258633 => Channel 0 WRITE
+2020-05-11 17:24:18,770 INFO [oak_runtime::runtime] Runtime instance dropped
+2020-05-11 17:24:18,770 DEBUG [oak_runtime::runtime::channel] last writer for channel 0 gone, wake waiters
+2020-05-11 17:24:18,770 DEBUG [oak_runtime::runtime::channel] dropping Channel object Channel { id=0, #readers=0, #writers=0, label=Label { secrecy_tags: [], integrity_tags: [] } }
+```
+
+The remainder of this document explores what's going on under the covers here,
+allowing individual stages to be built and run independently, and allowing
+builds that don't have to rely on a Docker environment.
+
## Meta-Advice
For any open-source project, the best way of figuring out what prerequisites and
