* add .python-version to .gitignore
* add .nvmrc to frontend
Also update DEVELOPER.md to mention optionally using nvm
* update DEVELOPER.md to reflect running successfully locally
* markdown autoformatter styling changes
* add slack permalink to alertgroup public api http response
* update changelog
* address PR comments
- rename permalink to permalinks in alert group public api seralizer
- add permalinks property to AlertGroup model
- update public api alert groups test
- update alertgroups public documentation to include permalinks property
* add default DEBUG = True in dev.py settings