Typography helpers

Change the size, weight, and other font properties of the text

There are 7 sizes to choose from, each of which can be combined with is-tiny and is-jumbo:

Class	Font-size	Tiny	Default	Jumbo
`is-size-1`	Tiny `0.75rem` Default `3rem` Jumbo `9rem`	Example	Example	Example
`is-size-2`	Tiny `0.65rem` Default `2.5rem` Jumbo `8rem`	Example	Example	Example
`is-size-3`	Tiny `0.55rem` Default `2rem` Jumbo `7rem`	Example	Example	Example
`is-size-4`	Tiny `0.45rem` Default `1.5rem` Jumbo `6rem`	Example	Example	Example
`is-size-5`	Tiny `0.35rem` Default `1.25rem` Jumbo `5rem`	Example	Example	Example
`is-size-6`	Tiny `0.25rem` Default `1rem` Jumbo `4rem`	Example	Example	Example
`is-size-7`	Tiny `0.15rem` Default `0.75rem` Jumbo `3rem`	Example	Example	Example