feat: building block for encoding

[muktihari]

• Now we have device mapping for Garmin devices (retrieved from Fit SDK) and Suunto devices (retrieved from Suunto website) and some devices that I own. We can update the device later by updating manufacturers.json if we get the list, and contributors can also contribute by adding the device that they own.

• Now we can see whether the WebAssembly is downloaded and instantiated by showing the loading, this to let users know if the decode process is slow might be due to initial usage and the browser need to download the wasm file.

instantiating-wasm.mov