Faucet and associated wiki page

[lsaether]

We now have a faucet set up at faucet.polkadot.chat (temporary URL). I'm currently in management of the faucet servers and keys but there are plans to transfer it over to Web3 DevOps instead and possibly move it to a different URL.

Before this happens there are a few things that should be done:

• Fix the backend
  • Remove intent from the URL.
  • Store the address and only allow 2 requests per address / day.
• Make a possibly nicer frontend
• Make better instructions on the page
• Modify tweet text to link back to the faucet page OR a wiki page about the faucet.

Justification

A faucet is useful to testers, builders, and operators of the Alexander testnet.

[laboon]

We may want to add better error-checking to this before it goes live, as well.

For example, it seems as though if you leave the default address in ("5xxxx..."), the faucet site asks if you've pasted the full link. I can imagine people going down the wrong path trying to fix that based on the error message.

[laboon]

When a PR for this comes in, we should probably also adjust the references to the BlockX Labs faucet ( https://faucets.blockxlabs.com/ ) or at least add ours in.

Currently these BlockX references are at ./docs/polkadot/node/guides/how-to-validate.md and ./docs/polkadot/learn/DOT.md but we should probably just do a grep -R before accepting.