Remove lineHeight unit from notes text

[treyhoover]

Description

Fixes an issue with notes overlapping in presenter view. (See image below for bug)

Type of Change

• Bug fix (non-breaking change which fixes an issue)

[treyhoover]

The issue is highlighted here: https://developer.mozilla.org/en-US/docs/Web/CSS/line-height#Prefer_unitless_numbers_for_line-height_values

@ryan-roemer, This is only an issue when using spectacle-mdx-loader because the generated html is slightly different (each note has an extra div). This change should resolve that, but we may want to create a separate issue for that project to standardize the html outputted.

[ryan-roemer]

Tested with one-page.html in this repository and yarn link-ed it to the private project that used spectacle-cli + MDX and the changes all look good everywhere! 🎉

[ryan-roemer]

@treyhoover -- Let's maybe also file the spectacle-mdx-loader issue with a lower priority just to track it as it would be nice to harmonize the outputs across JSX/MD/MDX modes.

[treyhoover]

@treyhoover -- Let's maybe also file the spectacle-mdx-loader issue with a lower priority just to track it as it would be nice to harmonize the outputs across JSX/MD/MDX modes.

Sure thing. Captured here.