Use revhistory, consolidate to one style guide

[tomschr]

This PR contains:

• Use <revhistory> tag and include it into <info> Create the necessary valid structure.
• Reformat docu_styleguide.changes.xml
• Remove obsolete DC-docu_styleguide_with_changes

---

This is just a proof-of-concept. To build it, use the following steps:

1. Clone the SUSE stylesheet repo somewhere:

   $ git clone --branch 577-use-revhistory git@github.com:openSUSE/suse-xsl.git

   If you already have this repo, make sure to switch to the 577-use-revhistory branch.

2. Switch to your local repo and get the latest changes of the style guide:

   $ cd $YOUR_LOCALREPO_PATH/doc-styleguide/ $ git switch main $ git pull -v $ git switch use-revhistory

3. Build the style guide with the path to the SUSE stylesheets from step 1:

   $ daps --styleroot=$PATH_TO_SUSE_XSL_REPO -vv -d DC-docu_styleguide html

   This will put all changelog entries into the title page. Probably not desirable.

4. To create a separate file, use the following parameter:

   $ daps --styleroot=$PATH_TO_SUSE_XSL_REPO -vv -d DC-docu_styleguide html --param enerate.revhistory.link=1

   This will put all changelog entries into a separate file. At the moment, there is not much layout or bling-bling attached. :wink:

5. Review the results.