Write an arrow tutorial #11219

In order to work out which arrow methods to keep, and which to deprecate and then remove, it would be good to write a tutorial about how to plot arrows in Matplotlib. A basic structure could be:

1. Plotting arrows in data space
2. Plotting arrows with the head/tail patches fixed in display space, but the beginning/end fixed in data space
3. Plotting arrows with everything in display space

Now I understand the transformation=... keyword argument better than I did when I wrote MEP29, I think I could have a good go at this.