add HTTPS warning, add geoFencePolygon()

readme.md

@@ -13,12 +13,13 @@ This activity is made possible by a research & planning grant from [Forecast Pub
 + [intervalCurrentPosition()](#intervalcurrentposition-used-with-a-callback)
 + [clearIntervalPos()](#clearintervalpos)
 + [calcGeoDistance()](#calcgeodistance)
-+ [geoFenceCircle()](#geoFenceCircle)
++ [geoFenceCircle()](#geofencecircle)
++ [geoFencePolygon()](#geofencepolygon)
 
 ##### Useful Tips
 + When using the p5.js editor, you must 'run in browser' to emulate or receive location events.
 + [How to Add a library to your p5.js sketch](https://github.com/processing/p5.js/wiki/Libraries#adding-a-library-to-your-project)
-+ IMPORTANT: Be aware that Google, Mozilla, Apple, Microsoft, are all in the process of banning several features from web pages that are served from HTTP instead of HTTPS (secure http)(https://sites.google.com/a/chromium.org/dev/Home/chromium-security/deprecating-powerful-features-on-insecure-origins) You can still do this but it needs to be over "secure origins" (such as HTTPS) and this can be done by purchasing a SSL certificate. Contact your hosting provide to see how this can be done. 
++ IMPORTANT: Be aware that Google, Mozilla, Apple, Microsoft, are all in the process of banning several features from web pages that are served from HTTP instead of HTTPS (secure http)(https://sites.google.com/a/chromium.org/dev/Home/chromium-security/deprecating-powerful-features-on-insecure-origins) You can still do this but it needs to be over "secure origins" (such as HTTPS) and this can be done by obtaining a SSL certificate. [Check out letsencrypt.org for a free & open option](https://letsencrypt.org/), or contact your hosting provider to see how this can be done. 
 
 ##### License
 p5.geolocaiton is licensed under the [GNU LGPL 2.1](http://choosealicense.com/licenses/lgpl-2.1/).