Add lightweight 2D WebGL cloud renderer as alternative to Vanta

build.py

@@ -73,6 +73,7 @@ def main():
         ('three', 'vendor/three.min.js'),
         ('suncalc', 'vendor/suncalc.js'),
         ('vanta2', 'vendor/vanta.clouds2.min.js'),
+        ('clouds2d', 'vendor/clouds2d.js'),
         ('i18n',  'i18n.js'),
         ('config', 'config.js'),
     ]: