Add guidance on when to use QuarkusMainTest #1205

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MicroProfile TCKs Tests	0s
matrix.java.name	0s
Kubernetes Tests - JDK ${{ matrix.java.name }}	0s
Gradle Tests - JDK ${{ matrix.java.name }}	0s
Native Tests - Virtual Thread - ${{ matrix.category }}	0s
Platform Tests - JDK ${{ matrix.java.name }}	0s
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	24m 49s

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