ES module support

This version removes the HTML import way of using this element because HTML imports are dead in favor of ES modules.

Change width attribute to columns

This is a breaking change that swaps the width attribute with the columns attribute. It felt weird to use the width attribute when we really just wanted the ASCII string to wrap at X columns.

Initial Release

The <ascii-image> custom element is similar to the <img> tag, but renders the image as ASCII art.

It currently supports two attributes:

• src is the location of the image (just like <img src="...">)
• width is the number of columns for the ASCII image.