Create a dedicated page for Telemetry information

[jenlampton]

Our official Telemetry policy is as follows:

We understand that privacy is important to you and we pledge the following. 

- We will not collect private or identifying information. No personal information will be stored on our servers. 
- We will always be transparent with people about what information is being  collected and how it is being used.
- We are collecting anonymous data for internal use only, but in the interest of transparency, the aggregated data will be made public for anyone to see.
- We will provide clear and transparent options to opt-out of sharing your own data.

We need to add this policy somewhere. Do we have a good place for it on the documentation site?

[stpaultim]

I created a draft page under appendix/reference.

https://docs.backdropcms.org/documentation/telemetry-policy