Add TXT record for verification

[kylemh]

b) Add a DNS TXT record with the name and value shown below.

     name        type        value
     _now        TXT         Qmd8XawRvuECtFLQm8SytbgcW2PV2jthtfMy7ujLnTN2gL

We will run a verification for you and you will receive an email upon completion.
If you want to force running a verification, you can run `now domains verify <domain>`
Read more: https://err.sh/now-cli/domain-verification