Update doc for IllegalInstantiation

[strkkk]

https://checkstyle.org/config_coding.html#IllegalInstantiation

Add example for each existing config to show what code is ok and what code cause violation.
Good example is https://checkstyle.org/config_naming.html#AbstractClassName
Look at referenced commits of #5832, to see what and how should be changed in code.

Please play with module/check by means of https://checkstyle.org/cmdline.html to understand how it works.

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PLEASE READ https://github.com/checkstyle/checkstyle/wiki/Good-practice-on-how-to-update-examples

[AmplifiedHuman]

I am on it

[AmplifiedHuman]

@strkkk
I am getting this error after running mvn clean verify
AllTestsTest.testAllTestsHaveProductionCode:68->walk:81->lambda$testAllTestsHaveProductionCode$3:69->grabAllFiles:115->getSimplePath:253 » StringIndexOutOfBounds
Is there a specific reason why this is happening?

[romani]

@AmplifiedHuman , please share full log of mvn verify execution by gitst.github.com , and please share your code changes. Can you send a PR with changes.

[himanshurijal]

I am on it.

[romani]

fix is merged.