fix: update start and stop scripts for Gateway services

[mattheworris]

While writing the documentation, there are some minor fixes. Here's the tracking list of them

• Should be be start-gateway.sh or just start.sh
• We should remove the default Provider Id from the setup script
• Update "DEFAULT seed phrase needed" -> "Required for Testnet"
• Remove script option for "Enter the location of the Content DB"

Closes #201

[mattheworris]

Changed to match SAT

[mattheworris]

Changed to match SAT

[mattheworris]

I don't think this is necessary for gateway now.

[claireolmstead]

Only question here... if we're pointing out that the seed phrase is required for testnet, we should probably point out that the provider id and some of the IPFS things are also required.

Additional solution: Change the IPFS default values based on if they select local or testnet?

[mattheworris]

Only question here... if we're pointing out that the seed phrase is required for testnet, we should probably point out that the provider id and some of the IPFS things are also required.

Additional solution: Change the IPFS default values based on if they select local or testnet?

PROVIDER_ID default is also "INPUT REQUIRED"

The IPFS defaults have been updated so that they should work with local and testnet.
(tracking an issue on SAT where IPFS links are not using the IPFS UA gateway to resolve, but I think all the gateway services are happy with these defaults)