You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allfileusages gafcontinue="BakalarskaPraca.zip|101" />
  </query-continue>
  <query>
    <pages>
      <page pageid="40" ns="0" title="Školský rok 2014/15" />
      <page pageid="59" ns="0" title="Školský rok 2015/16" />
      <page pageid="70" ns="0" title="Školský rok 2016/17" />
      <page pageid="77" ns="0" title="Školský rok 2017/18" />
      <page pageid="84" ns="0" title="Školský rok 2018/19" />
      <page pageid="90" ns="0" title="Školský rok 2019/20" />
      <page pageid="97" ns="0" title="Školský rok 2020/21" />
    </pages>
  </query>
</api>