Center videos

app.py

 import re
 
 RE_VID = re.compile("""\[video ["']([^['"]*?)["']\]""")
-TEMPLATE_VID = """<video controls><source src="{}" type="video/{}"></video>"""
+TEMPLATE_VID = """<video controls class="centered"><source src="{}" type="video/{}"></video>"""
 
 RE_SOUNDTRACK = re.compile("""\[soundtrack ["']([^['"]*?)["']\]""")
 TEMPLATE_SOUNDTRACK = """<audio loop data-autoplay><source src="{}" type="audio/{}"></audio>"""