Improve three scene performance and add JSCAD

- smoothed follow mouse animation
- made mobile friendlier down to about 330px ish
- added default social image
- used smaller hero asset

app/api/db/migrations/20210912041733_add_jscad/migration.sql

@@ -0,0 +1,2 @@
+-- AlterEnum
+ALTER TYPE "CadPackage" ADD VALUE 'jscad';