Add Canvas to html.py

Author: frmdstryr

web/components/html.py

@@ -769,6 +769,10 @@ def _update_proxy(self, change: ChangeDict):
         super()._update_proxy(change)
 
 
+class Canvas(Tag):
+    tag = "canvas"
+
+
 class Video(Tag):
     tag = "video"
     controls = d_(Coerced(bool))