Update doc for MethodLength #11474
Description
https://checkstyle.org/config_sizes.html#MethodLength
Add example for each existing config to show what code is ok and what code cause violation.
A 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.
PLEASE READ https://github.com/checkstyle/checkstyle/wiki/Good-practice-on-how-to-update-examples