Plainpage 1.0.2

Housekeeping. No visual change.

• minAppVersion raised to 1.8.0. The lint warnings about partially supported browser features are measured against minAppVersion, so the CSS was being judged against Obsidian 1.4.5, from 2023.
• 24 redundant -webkit-mask-* declarations removed. Each had an unprefixed twin with the same value.
• One grid now uses the gap shorthand instead of column-gap/row-gap.

theme.css is 131 KB -> 124 KB.

If you are on Obsidian older than 1.8.0, stay on 1.0.1.