This script makes it easy to update the web page at
https://google.github.io/filament/remote/ even if you do not have the
emscripten SDK. It works by downloadinug the latest continuous web
build, then placing the wasm file in the right place.
After running the script, the user must make a git commit to finish the
operation.
Shockingly there were no unit tests that did a simple write-then-read.
This is important because it's easy to forget details such as trailing
commas and the fact that uint8_t is a char.
