Created by: thomaswelton
Added new variable @line-height-target with a default value to 20px to match the existing style.
Then updated @line-height-base so it was no longer a magic number with a comment of 20 / 14
Seeing as this value was using math I've made it more explicit. The @line-height-base is now a unitless value derived from the base font size and new line height target.
Seeing as now the @line-height-base is variable driven I removed it from the customiser along with@line-height-computed
I think this may make it easier for people to customise the variables file and get the values they want without have to do the math themselves, and seems a lot more explicit.
Note: Would this now make @line-height-computed redundant? I've kept it it for compatibility but could this variable become deprecated in a future release?