readme: draft out the initial cli interface
# h2olog
[BPF](https://www.kernel.org/doc/html/latest/bpf/index.html) ([kernel doc](https://www.kernel.org/doc/Documentation/networking/filter.txt)) backed request logging client for the [H2O](https://github.com/h2o/h2o) server.
+
+## Quickstart
+
+```
+$ h2olog -p $(pgrep -o h2o)
+```
