[Documentation] Describe JDK module requirements for target application

### Current Behavior

No information about JDK requirements for target application on https://cryostat.io/get-started/#using-jmx

### Expected Behavior

Note what JDK requirements are needed for JMX to work

### Steps To Reproduce

https://github.com/cryostatio/cryostat/discussions/595

Discussion follow up:
* for JDK 17 some modules are needed (like `jdk.management.jfr` and `jdk.management`) and it should be documented to avoid confusing errors

### Environment

```Markdown
- OS:
- Environment:
- Version:
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### Anything else?

_No response_