Extract monospace text styling to a %placeholder

Currently only `` `

` etc elements provide built-in monospace font styling, but they also come with other styles, like background, etc.


There is no easy way of creating other elements that will use monospace font but different style.

We should extract any necessary styles (font, line-height, etc) to some `%vf-text-monospace` placeholder, so it can be reused in places that need to use monospace font without inheriting base `` styling.

Locate the existing styles for code and pre elements and identify the shared monospace font and line-height rules. Extract those necessary styles into a reusable %vf-text-monospace placeholder without carrying over backgrounds or other code styling. Done means other elements can reuse the monospace styling independently.

Written by the indexing model from the issue text.