text: Title: Replace Weasyprint with PDFkit
  Body: https://github.com/JazzCore/python-pdfkit
  
  Renders better
  
  We need to create an option `?clean=true` which will render pure content without js and css transformations to fit in PDF pages. Also an url `url_for('export_to_pdf', 'article-long-slug')` that will call a localhost url and returns the html file to the browser 
  