message: Fly QGC Mission example: Update path of sample plan
diff: *
  * Steps to run this example:
  * 1. (a) Create a Mission in QGroundControl and save them to a file (.plan) (OR)
  -* (b) Use a pre-created sample mission plan in "example/fly_qgc_mission/qgroundcontrol_sample.plan".
  +* (b) Use a pre-created sample mission plan in "plugins/mission/qgroundcontrol_sample.plan".
  * Click [here](https://user-images.githubusercontent.com/26615772/31763673-972c5bb6-b4dc-11e7-8ff0-f8b39b6b88c3.png) to see what sample mission plan in QGroundControl looks like.
  -* 2. Run the example by passing path of the QGC mission plan as argument (Uses sample mission plan by default).
  +* 2. Run the example by passing path of the QGC mission plan as argument (By default, sample mission plan is imported).
  *
  * Example description:
  * 1. Imports QGC mission items from .plan file.
  