Add xml extraction script

data/Wikipedia-20181120103842.xml

-<mediawiki xmlns="http://www.mediawiki.org/xml/export-0.10/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mediawiki.org/xml/export-0.10/ http://www.mediawiki.org/xml/export-0.10.xsd" version="0.10" xml:lang="en">
+<mediawiki xml:lang="en">
   <siteinfo>
     <sitename>Wikipedia</sitename>
     <dbname>enwiki</dbname>