from #15712 (review)

Two items:

• move all // violation ..... out of javadoc
• resolve supplemental: added violation messages in JavadocParagraph's input files #15712 (comment) by split some code to new Input file
• // '\<p\> tag should be placed immediately before the first word' not clear why escaping is required.
• remove /^ WARN/ text as they can affect validation