moved img to editable section

[estelle]

I moved the

img {
max-width: 100%;
}

to the editable section because I think people need to understand why the image is behaving the way it is.

[rachelandrew]

This is covered in the overflow section. I don't normally clutter each example with all of the stuff from other examples, preferring to demonstrate one thing at a time.

[rachelandrew]

See: https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_Columns/Handling_Overflow_in_Multicol