Update help text to properly display the url

[mariari]

As it currently stands the help text renders like

namadac utils join-network --help
...
OPTIONS:
        --chain-id <chain-id>
            The chain ID. The chain must be known in the https://github.com/heliaxdev/anoma-network-
            config repository.

which causes issues as upon a quick glance or click the url is https://github.com/heliaxdev/anoma-network-. I have changed the text so it's properly kept in tact

 % namadac utils join-network  --help
...
OPTIONS:
        --chain-id <chain-id>
            The chain ID. The chain must be known in the repository:
            https://github.com/heliaxdev/anoma-network-config

now the link can properly be clicked from the terminal and people at a click glance won't confuse the url