Update README.

README.md

@@ -22,14 +22,20 @@ randomize keys/certificates used for issuance.
 
 Pebble aims to address the need for ACME clients to have an easier to use,
 self-contained version of Boulder to test their clients against while developing
-ACME-04 support. Boulder is multi-process, requires heavy dependencies (MariaDB,
+ACME-06 support. Boulder is multi-process, requires heavy dependencies (MariaDB,
 RabbitMQ, etc), and is operationally complex to integrate with other projects.
 
 Where possible Pebble aims to produce code that can be used to inform the
 pending Boulder support for ACME-06, through contribution of code as well as
 design lessons learned. Development of Pebble is meant to be rapid, and to
 produce a minimum working prototype on a short schedule.
 
+In places where the ACME specification allows customization/CA choice Pebble
+aims to make choices different from Boulder. For instance, Pebble changes the
+path structures for its resources and directory endpoints to differ from
+Boulder. The goal is to emphasize client specification compatibility and to
+avoid "over-fitting" on Boulder and the Let's Encrypt production service.
+
 Lastly, Pebble will enforce it's test-only usage by aggressively building in
 guardrails that make using it in a production setting impossible or very
 inconvenient. Pebble will not support non-volatile storage or persistence
@@ -48,3 +54,17 @@ clients are not hardcoding URLs.)
 ## Usage
 
 `pebble -config ./test/config/pebble-config.json`
+
+## Issuance
+
+The easiest way to test issue with Pebble is to use `chisel2` from the
+`acme-v2` certbot branch (this is a work in progress).
+
+1. `git clone -b acme-v2 https://github.com/certbot/certbot`
+2. `cd certbot`
+3. `letsencrypt-auto-source/letsencrypt-auto --os-packages-only`
+4. `./tools/venv.sh`
+5. `. venev/bin/activate`
+6. `python ./certbot/tools/chisel2.py example.com`
+
+