Implemented latest article view
* the first paragraph of the three latest articles of my blog are now displayed on the overview page
* feed is fetched via `curl` in `01_raw/article_feed.xsl`
** as with all commit feeds the article feed is processed further in the `02_augment` level
** the count of articles to be displayed is defined in `00_content/meta.xml` as `article_count`
* CSS was updated to correctly display the article summary