Added standard code of conduct file

[helpfulrobot]

Hello!

I'm helpful robot. Ever seen two robots fighting over code? That's because most of us know the robot code of conduct. Did you know SilverStripe has a code of conduct, for community interaction?

Have a nice day! [tick tick tick]

[nglasl]

Thank you for your contribution here. I just wanted to let you know that we’re looking to improve our management of issues and pull requests, with a goal to providing clear direction on how Symbiote contributes to the open source community. As part of this ongoing effort:

• issues and pull requests that have been open prior to December 2017 with no recent activity are being closed

  • this is included

  • if you can confirm this remains applicable for SS3.6+ please do open it again

• remaining issues and pull requests will be

  • categorised

  • on a clear path to resolution (whatever the next step may be).

This ultimately brings us one step closer to our ambition; being able to prioritise current issues and contributions in a timely manner. If you have any questions, please see https://www.symbiote.com.au/contributing for further information.