Request: Add support for sizing ceil/floor as delimiters

[ghost]

\left and \right, and the variants of \big and \small work as expected on usual delimiters such as brackets and angle brackets, but they don't work on ceil and floor operators.

This is specifically awkward when using these operations on fractions, since they require a larger sized delimiter to look sensible.

For instance, this:

$$
\left \lceil \frac{a}{b} \right \rceil
$$

Currently the left and right are simply ignored. Which leads to too-small ceiling (and floor) symbols.

[gjtorikian]

Makes sense; I'll add it to my backlog.

[ghost]

Awesome, thanks 👍