Add Ponyville examples of comments

Author: yvovandoorn

REFERENCE.md

@@ -189,7 +189,7 @@ program:
 | `date`             | Yes      | The date of the program element, in YYYY-MM-DD format.                                                                                                                                                                                      | 2017-06-16                                                                                              |
 | `start_time`       | Yes      | The start time of the program element.                                                                                                                                                                                                      | "08:00"                                                                                                 |
 | `end_time`         | Yes      | The end time of the program element.                                                                                                                                                                                                        | "13:40"                                                                                                 |
-| `comments`         | No       | Additional comments/notes about the program element (for example, location of an evening event). Markdown is supported.                                                                                                                     | "This will be at the [Pony Club](http://www.mattstratton.com),1005 Ponyville Drive,Ponyville, IL,60612" |
+| `comments`         | No       | Additional comments/notes about the program types `talk`, `workshop` and `custom` (for example, location of an evening event). Markdown is supported.                                                                                                                     | "This will be at the [Pony Club](http://www.mattstratton.com),1005 Ponyville Drive,Ponyville, IL,60612" |
 | `background_color` | No       | Allows the ability to override the color of the program element. Only the background color can be changed; please test to make sure the color works with the displayed text colors. Color is expressed in RGB HEX value. Must be in quotes. | "#FFFA99"                                                                                            |
 
 ##### Program Element Colors

exampleSite/data/events/2017-ponyville.yml

@@ -197,6 +197,7 @@ program:
     date: 2017-07-16
     start_time: "09:15"
     end_time: "09:45"
+    comments: "Talk located in Main Room"
   - title: "Sponsors"
     type: custom
     date: 2017-07-16
@@ -252,6 +253,12 @@ program:
     date: 2017-07-16
     start_time: "14:15"
     end_time: "15:00"
+  - title: "twilight-sparkle"
+    type: talk
+    date: 2017-07-16
+    start_time: "14:15"
+    end_time: "15:00"
+    comments: "Alternative Track | Located in other room"
   - title: "Break"
     type: workshop
     date: 2017-07-16