Docs: Feedback for 'Self-Contained docToolchain' - local tasks

Hello the way the ps1 is doing the java version calculation does not work in windows.
This makes the command .dtwc local tasks to fail on the dtcw.ps1.

1. the command being used java -version -> Is not working the correct is java --version
`# We got a Java version
$javaversion = ((Invoke-Expression -Command "$JAVA_CMD -version 2>&1"`

2. the output is parsed incorrectly

Current output of java version
"
Java 17.0.8 2023-07-18 LTS
Java(TM) SE Runtime Environment (build 17.0.8+9-LTS-211)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.8+9-LTS-211, mixed mode, sharing)
"

Parsing rules:
$javaversion = ((Invoke-Expression -Command "$JAVA_CMD --version 2>&1" | Select-String -Pattern 'version').Line | Select-Object -First 1 ).Split('"')[1].Split(".")[0]

There is no patter as 'version'. Result is null

---
#page: https://github.com/doctoolchain/doctoolchain/edit/ng/src/docs/020_tutorial/120_self-contained-dtc.adoc
#branch: ng

Start with the self-contained docToolchain page at docs/020_tutorial/120_self-contained-dtc.adoc and the referenced dtcw.ps1 logic for .dtcw local tasks. Check the Windows Java version command and parsing against the shown Java output; done means the local tasks command can determine the Java version successfully on Windows.

Written by the indexing model from the issue text.