This matches the W008 and W047 warnings that JSHint already emits for us.
(As seen at https://code.wildfiregames.com/D1993#83345).
The equivalent rule in ESLint is `no-floating-decimal`. Enable this so developers can
detect this while writing code in IDEs with an ESLint plugin (which is more widely
available than the now-lesser maintainer JSHint, and more contributors will have
this installed already).
It also means we can auto-fix them in the future with `eslint --fix`.
This commit fixes the one violation that existed in the code base, so enabling this
won't add any Vulcan noise.
https://eslint.org/docs/rules/no-floating-decimal