Webassembly App example uses 3rd party repo

[JTorreG]

The steps in the HOW-TO > App Samples > WebAssembly doc (source ) include cloning a 3rd party repo that we have no control over (potential security risk if a malicious agent would modify the contents of that repo).

We should replace this example with our own solution.

[JTorreG]

Will need some help finding what to replace this repo with

cc @callahad