HTMLs in the description is no longer displayed without escaping for SECURITY-353.

To fix:

• use `ParameterDefinition#getFormattedDescription` introduced in Jenkins-1.521.
  • 1.532 is the least LTS.
• Set `escapeEntryTitleAndDescription` to false.

It might be useful if itroducing the previewing feature like this:

    <f:textarea name="parameter.description" value="${instance.description}" codemirror-mode="${app.markupFormatter.codeMirrorMode}" codemirror-config="${app.markupFormatter.codeMirrorConfig}" previewEndpoint="/markupFormatter/previewDescription" />

• This is introduced since Jenkins-1.554.