Make compilation with typescript compiler possible with decorators

[QuadratClown]

As mentioned in the docs:

While it is most likely possible to use the typescript compiler with the decorators as well, in the compilation of the package the plugin @babel/plugin-transform-typescript was used for code transpiling.

Trying to compile with the typescript compiler currently throws an error

/app/node_modules/dbus-next/lib/service/interface.js:158
    options.fn = descriptor.descriptor.value;
                                       ^

TypeError: Cannot read property 'value' of undefined
    at /app/node_modules/dbus-next/lib/service/interface.js:158:40
    at __decorate (/app/dist/WifiAdvertisement.js:5:110)
    at Object.<anonymous> (/app/dist/WifiAdvertisement.js:32:1)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (/app/dist/WifiBluetoothServer.js:5:29)

Issue raised by @ErwinSteffens in #7 (comment)