[docs] Add gnolang/faucet

[leohhhn]

Description

This issue concerns adding the gnolang/faucet tool to the docs. This involves:

• Adding a gnolang/faucet reference page in the Gno Tooling section,
• Adding a tutorial in the new Gno Infra section for setting up and running a faucet.

[leohhhn]

Running into some questions:

• What kind of security against DDoS do we have implemented in the faucet?
• What are the request types the faucet can take?
• How do you actually send batch requests to the faucet?

[leohhhn]

What is the difference between these flags?

-config string                  the path to the command configuration file [TOML]
-faucet-config string           the path to the faucet TOML configuration, if any