add privacy policy

TODO.md

@@ -24,6 +24,7 @@
 * How do avalanche beacons work?  Could this do that as well?  possibly by using beacon mode feature of the RF95?
 * use std::map<BLECharacteristic*, std::string> in node db
 * first alpha release, article writeup
+* send note about Adafruit Clue
 * send pr https://github.com/ThingPulse/esp8266-oled-ssd1306 to tell them about this project
 
 # Low power consumption tasks

docs/privacy.md

@@ -0,0 +1,11 @@
+# Meshtastic privacy policy
+
+We don't collect any personal identifying information.  
+
+If you have opted-in to analytics (thank you - that helps us know what things we need to improve), we'll receive anonomized information about user behavior.  i.e. where you went in the app etc...  We never
+capture usernames, the contents of your texts.
+
+This is an open-source project run by hobbyists and we try to be completely transparent.  If you have questions on this policy, please file [a github issue](https://github.com/geeksville/meshtastic-esp32/issues) and we'll reply/clarify/correct.
+
+Keep being awesome!
+