Add modern plugin skeleton #1

Job	Run time
all / code-style / PHP CodeSniffer	24s
all / create-matrix / create-matrix	3s
all / auto-fix / Automatic Code Style Fixing	52s
all / test-stable / PHP 7.4 DokuWiki stable	1m 13s
all / test-master / PHP 7.4 DokuWiki master	1m 6s
all / test-stable / PHP 8.0 DokuWiki stable	1m 9s
all / test-master / PHP 8.0 DokuWiki master	1m 12s
all / test-stable / PHP 8.1 DokuWiki stable	1m 6s
all / test-master / PHP 8.1 DokuWiki master	1m 8s
all / test-stable / PHP 8.2 DokuWiki stable	1m 10s
all / test-master / PHP 8.2 DokuWiki master	1m 11s
all / test-stable / PHP 8.3 DokuWiki stable	1m 2s
all / test-master / PHP 8.3 DokuWiki master	1m 3s
	12m 39s

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