v0.3.1

Fixed

• In a <foreignObject>, collapsible white space on either side of a <br> goes, as at the end and the start
  of any line in Chromium. draw.io writes HTML labels indented, with a newline before each <br/>: WeasyPrint
  kept a space at the end of each line, which moved centered text left by half a space, and white space after
  the last <br/> made an empty line, which moved a label centered in a flex box up. A label of pdf-exporter
  sat 10.8 px left and 5 px above Chromium, and now matches it.

Full changelog: v0.3.0...v0.3.1