Point default config file to default lnd install

Config file. Also make sure you use `os.expandpath` to expand the `~`.

```
[LND]
# Replace the below values with your respective files for your
# lnd node

MacaroonPath = ~/.lnd/data/chain/bitcoin/mainnet/admin.macaroon
TlsCert = ~/.lnd/tls.cert
Host = localhost:10009

[LNT]
```