Update development setup section of CONTRIBUTING

CONTRIBUTING.md

@@ -41,11 +41,12 @@ Here are a few things you can do that will increase the likelihood of your pull
 ## Development setup
 
 ```
-pip install -r requirements.txt
-pip install -r requirements-dev.txt
-python setup.py install
+./scipt/bootstrap
+source env/bin/activate
 ```
 
+See the [`scripts/`](/scripts) if you'd like to run tests and coverage ([`script/coverage/`](/scripts/coverage)) and coverage ([`script/lint`](/scripts/lint)). After bootstrapping and sourcing the `env/` commands in the [`octodns/cmds/`](/octodns/cmds) directory can be run with `PYTHONPATH=. ./octodns/cmds/sync.py ...`
+
 ## License note
 
 We can only accept contributions that are compatible with the MIT license.