Add markdownlint config and action for V2 #230

Job	Run time
bullseye armv7 / build	17m 44s
bookworm armv7 / build	16m 41s
bookworm armv7 / test (pi, run_installation_classic.sh)	11m 39s
bookworm armv7 / test (pi, run_installation_rfid.sh)	12m 28s
bookworm armv7 / test (pi, run_installation_spotify.sh)	15m 26s
bookworm armv7 / test (pi, run_installation_staticip_dhcpcd.sh)	11m 53s
bookworm armv7 / test (pi, run_installation_autohotspot_dhcpcd.sh)	13m 20s
bookworm armv7 / test (pi, run_installation_autohotspot_NetworkManager.sh)	12m 20s
bookworm armv7 / test (hans, run_installation_classic.sh)	54s
bullseye armv7 / test (pi, run_installation_classic.sh)	4m 41s
bullseye armv7 / test (pi, run_installation_rfid.sh)	4m 47s
bullseye armv7 / test (pi, run_installation_spotify.sh)	10m 57s
bullseye armv7 / test (pi, run_installation_staticip_dhcpcd.sh)	4m 43s
bullseye armv7 / test (pi, run_installation_autohotspot_dhcpcd.sh)	5m 25s
bullseye armv7 / test (pi, run_installation_autohotspot_NetworkManager.sh)	5m 57s
bullseye armv7 / test (hans, run_installation_classic.sh)	1m 4s
bullseye armv7 / cleanup	4s
bookworm armv7 / cleanup	5s
	2h 30m 8s

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