Add (or is it missing?) visual aid to illustrate feedback axis

[mikemhenry]

For episodes/11-practice-teaching.md it would be nice to have a visual aid of the

"Organize your feedback along two axes: positive vs. opportunities for growth (sometimes called “negative”) and content (what was said) vs. presentation (how it was said)."

I had thought the lesson used to have a chart/plot of this, but I could be misremembering it. A little chart of each axis and an example sentence for each spot would go along way IMHO.

[brownsarahm]

we have it in the stock slides, but I do not know if it has ever been here. It could be added though