private boolean isValidHelpURL(URL url) {
		if (url == null) {
			return false;
		}
		String file = url.getFile();
		return new File(file).exists();
	}
Enables the Find Dialog for searching through the current page of a help document.
Ghidra/Framework/Docking/src/main/java/docking/help/HelpViewSearcher.java