Xdoc generation should be in mvn site phase

[stoyanK7]

The final step of this project is to have the generation happen in mvn site phase. As of now, we use a @BeforeAll method in XdocsPagesTest to generate Xdocs. We use a custom parser, custom sink, and custom sink factory. The reason we have them is because we want to isolate macro execution from parsing the rest of the file to HTML. Once the whole repository is converted to templates and we are certain the generation is good, those 3 modules will be removed. The default XdocParser in mvn site phase will execute the macros and parse to HTML for us.

please beware of #13770 fix that introduced extra overrides to doxia files that might cause extra complexity in this issue. Completing #13426 means we will be removing the classes we copied and hacked from Doxia (XdocsTemplateSink) which is documented at

checkstyle/src/main/java/com/puppycrawl/tools/checkstyle/site/XdocsTemplateSink.java

Lines 33 to 34 in f6b70cc

	* This module will be removed once
	* <a href="https://github.com/checkstyle/checkstyle/issues/13426">#13426</a> is resolved.

. When completing #13426 and removing the class, we need to re-open #13770 and find a permanent fix unless doxia resolves our internal issues at https://issues.apache.org/jira/browse/DOXIA-707 .

Interesting note at https://issues.apache.org/jira/browse/DOXIA-707

Since you want to migrate to a Maven Site Plugin approach, you don't need to generate XDoc at all. kwin, has just migrated Maven Plugin Tools off XDoc to an abstract sink provided by Maven Reporting Impl.

[romani]

We should do this only as very last issue, as it has no much benefit to users and simply design beautification, that is also good, but we have bunch of other issues to be done first.

[rnveach]

it has no much benefit to users and simply design beautification

That describes this whole project.