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="Iota_tutorial_12_05182018.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="145" ns="6" title="File:Cppxfel dials after threshold.png" />
      <page pageid="144" ns="6" title="File:Cppxfel dials spot finding parameters.png" />
      <page pageid="143" ns="6" title="File:Cppxfel dials threshold before.png" />
      <page pageid="71" ns="6" title="File:Cspadmetrology.png" />
      <page pageid="210" ns="6" title="File:Iota analysis screen 08022019.png" />
      <page pageid="206" ns="6" title="File:Iota main screen 08022019.png" />
      <page pageid="208" ns="6" title="File:Iota proc settings screen 08022019.png" />
      <page pageid="209" ns="6" title="File:Iota run screen 08022019.png" />
      <page pageid="204" ns="6" title="File:Iota tutorial 10 08022019.png" />
      <page pageid="205" ns="6" title="File:Iota tutorial 11 08022019.png" />
    </pages>
  </query>
</api>