Update the getting started commands.
Update the getting started commands.

Doing an `npm install bitcore-wallet-service` wouldn't install the project in the directory since there is no `package.json` file. It should rather be a `git clone` and then `cd bitcore-wallet-service && npm start`.
bitjson/bitcore,bitjson/bitcore,martindale/bitcore,bitpay/bitcore,matiu/bitcore-wallet-service,bitjson/bitcore,bitpay/bitcore,bitpay/bitcore-wallet-service,bitpay/bitcore,matiu/bitcore-wallet-service,martindale/bitcore,janko33bd/bitcore-wallet-service,bitjson/bitcore,janko33bd/bitcore-wallet-service,martindale/bitcore,bitpay/bitcore-wallet-service,bitpay/bitcore,martindale/bitcore