Add activity to "kinds of contribution" slide in intro presentation

[shaunagm]

The "kinds of contributions" slide of the "what is open source" presentation could be more interactive and meaningful.

We brainstormed the following activity: the presenter asks if anyone in the room has made one of the kinds of contributions listed, and asks them to talk about what that was like and what was involved. Another activity I just came up with: asking students to come up with three different ways they could contribute (or want to learn how to contribute).

Steps to address this issue:

• pick an activity to be the default activity
• add an explanation of how to run the activity into the speaker notes of the slide
• add additional prompt text to the visual slide as needed

If the activity can be done in a self-guided way, make sure to add the activity to both the presenter-led and self-guided versions.