Add new faucets' details to the documentation

[5A11]

There are new faucets. Message from Ian:

I've modified the token faucet app so that it can provide tokens other than fet (or, more pedantically, provide tokens other than those in which it's paying the gas), and spun up separate faucets for each denom in the dorado testnet... get some atestfet (no change here!) curl -X POST -H 'Content-Type: application/json' -d '{"address":"fetch1tester2p8g2726furxwl7kvmxu49et7vd8ucum"}' https://faucet-dorado.fetch.ai/api/v3/claims

get some nanomobx curl -X POST -H 'Content-Type: application/json' -d '{"address":"fetch1tester2p8g2726furxwl7kvmxu49et7vd8ucum"}' https://faucet-mobx-dorado.fetch.ai/api/v3/claims

get some ulrn curl -X POST -H 'Content-Type: application/json' -d '{"address":"fetch1tester2p8g2726furxwl7kvmxu49et7vd8ucum"}' https://faucet-lrn-dorado.fetch.ai/api/v3/claims

results in... fetchd query bank balances fetch1tester2p8g2726furxwl7kvmxu49et7vd8ucum balances:

• amount: "10000000000000000000" denom: atestfet
• amount: "1000" denom: nanomobx
• amount: "1000" denom: ulrn https://explore-dorado.t-v3-london.fetch-ai.com/account/fetch1tester2p8g2726furxwl7kvmxu49et7vd8ucum

Add these details to the documentation.