documentation: add dedicated "articles" section

We are preparing to import yet another article about Jailhouse, so
it makes sense to have dedicated place to store them. Also, add a
timestamp to article's filename, so one can easily say its
publication date.

Signed-off-by: Valentine Sinitsyn <valentine.sinitsyn@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>

diff --git a/Documentation/LWN.net-article.txt b/Documentation/articles/LWN.net-article-01-2014.txt
similarity index 100%
rename from Documentation/LWN.net-article.txt
rename to Documentation/articles/LWN.net-article-01-2014.txt