Introduce docc documentation and "supported features" #757

Job	Run time
Test (Java) (jammy swift:6.1.2 jdk:corretto)	2m 37s
Documentation check (6.1.2, corretto)	1m 59s
Test (Java) (macos swift:6.1.2 jdk:corretto)	2m 11s
Sample JavaSieve (macos swift:6.1.2 jdk:corretto)	2m 27s
Test (Swift) (jammy swift:6.1.2 jdk:corretto)	4m 31s
Sample JavaKitSampleApp (macos swift:6.1.2 jdk:corretto)	4m 18s
Sample JavaProbablyPrime (macos swift:6.1.2 jdk:corretto)	39s
Benchmark (JMH) (jammy swift:6.1.2 jdk:corretto)	7m 21s
Sample JExtractJNISampleApp (macos swift:6.1.2 jdk:corretto)	1s
Sample SwiftAndJavaJarSampleLib (macos swift:6.1.2 jdk:corretto)	1s
Sample JavaDependencySampleApp (macos swift:6.1.2 jdk:corretto)	1s
Sample SwiftKitSampleApp (macos swift:6.1.2 jdk:corretto)	14m 38s
Test (Swift) (macos swift:6.1.2 jdk:corretto)	1s
Sample SwiftKitSampleApp (jammy swift:6.1.2 jdk:corretto)	5m 35s
Sample JavaSieve (jammy swift:6.1.2 jdk:corretto)	45s
Sample JavaProbablyPrime (jammy swift:6.1.2 jdk:corretto)	3m 24s
Sample JavaKitSampleApp (jammy swift:6.1.2 jdk:corretto)	3m 31s
Sample SwiftAndJavaJarSampleLib (jammy swift:6.1.2 jdk:corretto)	4m 26s
Sample JavaDependencySampleApp (jammy swift:6.1.2 jdk:corretto)	5m 57s
Sample JExtractJNISampleApp (jammy swift:6.1.2 jdk:corretto)	5m 27s
soundness / License headers check	6s
soundness / Unacceptable language check	3s
soundness / YAML lint check	5s
soundness / Shell check	32s
soundness / Python lint check	10s
soundness / Broken symlinks check	4s
soundness / Format check	0s
soundness / Documentation check	0s
soundness / API breakage check	0s
	1h 10m 50s

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