Improve "Add a Currency" docs (#546)

Author: sindresorhus

docs/add-currency.md

@@ -5,7 +5,7 @@ Instructions for getting a new cryptocurrency added to HyperDEX.
 ## Requirements
 
 - The currency must be [Bitcoin-compatible](https://docs.komodoplatform.com/barterDEX/get-listed-barterDEX.html) or ERC20-based.
-- If the currency is not ERC20-based, there must be at least 2 trusted Electrum servers for the currency. The servers should available on domains/subdomains, not IP addresses. Preferably subdomains on the official domain. Say the domain is `currency.com`, the Electrum servers should be at `electrum1.currency.com` and `electrum2.currency.com`.
+- If the currency is not ERC20-based, there must be at least 2 trusted Electrum servers for the currency. The servers should available on domains/subdomains, not IP addresses. Preferably subdomains on the official domain. Say the domain is `currency.com`, the Electrum servers should be at `electrum1.currency.com` and `electrum2.currency.com`. You also need to commit to keeping the Electrum servers running, and if they need to be taken down, give us due notice to make changes.
 
 ## Proof
 
@@ -24,4 +24,7 @@ Examples:
 - When your pull request to `jl777/coins` has been merged, you can open a pull request on https://github.com/atomiclabs/hyperdex.
 	- Add the currency info [here](https://github.com/atomiclabs/hyperdex/blob/master/app/marketmaker/supported-currencies.js). *Note that the list is ordered alphabetically.*
 	- Add the block explorer [here](https://github.com/atomiclabs/hyperdex/blob/master/app/renderer/block-explorer.js). *Note that the list is ordered alphabetically.*
-	- In the pull request description, include information about the currency, like official website, CoinMarketCap page, Twitter, etc. Also include a link to your `jl777/coins` pull request.
+		- It should be a URL, not an IP address. Preferably a subdomain on the official domain. So if the domain is `currency.com`, then it should be available on `https://explorer.currency.com/tx`.
+		- We strongly recommend using HTTPS for the site.
+	- The title of the pull request should be `Add Name (SYMBOL) currency`. For example, `Add FooCoin (FOO) currency`.
+	- In the pull request description, include information about the currency, like the official website, CoinMarketCap page, Twitter, etc. Also include a link to your `jl777/coins` pull request. And if applicable, a link to your issue on the `cryptocurrency-icons` repo.