feat(theme): Branded theming via brand.yml #2973

Job	Run time
routine / routine	7m 3s
website / pkgdown	10m 13s
R-CMD-check / setup	15s
R-CMD-check / macOS-latest (4.4.2)	2m 41s
R-CMD-check / windows-latest (4.4.2)	3m 58s
R-CMD-check / ubuntu-latest (devel)	2m 24s
R-CMD-check / ubuntu-latest (4.4.2)	2m 12s
R-CMD-check / ubuntu-latest (4.3.3)	2m 17s
R-CMD-check / ubuntu-latest (4.2.3)	2m 28s
R-CMD-check / ubuntu-latest (4.1.3)	2m 35s
R-CMD-check / ubuntu-latest (4.0.5)	2m 25s
Deploy to shinyapps.io	0s
	38m 31s

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