When the user presses return to create a new line, we should auto-indent the new line for them.

The amount of indentation to give the new line will be based on the previous line's indentation, or if the previous line ends in a {, [, (, or <, increase the indent.

If there is a matching }, ], ), or >, we need to add it to a new line underneath the new line and indent it the same amount of indentation as the original line the user was on before they created the new line.

Related

• ✨ Matching tag and bracket pairs #79