Bump stylelint from 15.6.0 to 16.14.0 #105

Job	Run time
Build (jekyll gem) (3.9, ubuntu-latest, 2.7)	59s
Test CSS and JS (18.x)	3s
Build (jekyll gem) (3.9, ubuntu-latest, 3.1)	21s
Build (github-pages gem)	40s
Build (jekyll gem) (3.9, macos-latest, 2.7)	1m 21s
Build (jekyll gem) (3.9, macos-latest, 3.1)	25s
Build (jekyll gem) (3.9, windows-latest, 2.7)	2m 43s
Build (jekyll gem) (3.9, windows-latest, 3.1)	2m 5s
Build (jekyll gem) (4.3, ubuntu-latest, 2.7)	1m 23s
Build (jekyll gem) (4.3, ubuntu-latest, 3.1)	35s
Build (jekyll gem) (4.3, macos-latest, 2.7)	1m 26s
Build (jekyll gem) (4.3, macos-latest, 3.1)	33s
Build (jekyll gem) (4.3, windows-latest, 2.7)	4m 39s
Build (jekyll gem) (4.3, windows-latest, 3.1)	2m 14s
	19m 27s

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