[#2473] Convert main buttons to NLDS #8058

Job	Run time
Build and check documentation	1m 37s
End-to-end tests, chromium	4m 31s
Check that documentation for configuration steps is up-to-date	1m 28s
End-to-end tests, firefox	4m 31s
End-to-end tests, webkit	4m 14s
Run the Django test suite (main)	19m 50s
End-to-end tests, msedge	4m 32s
Run the Django test suite (elastic)	5m 32s
Run the Django test suite (openklant)	2m 34s
Upload coverage information to codecov	15s
Build (and push) Docker image	1m 47s
	50m 51s

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