Document bitvavo as community tested

closes #4360

README.md

@@ -22,12 +22,21 @@ expect.
 We strongly recommend you to have coding and Python knowledge. Do not
 hesitate to read the source code and understand the mechanism of this bot.
 
-## Exchange marketplaces supported
+## Supported Exchange marketplaces
+
+Please read the [exchange specific notes](docs/exchanges.md) to learn about eventual, special configurations needed for each exchange.
 
 - [X] [Bittrex](https://bittrex.com/)
 - [X] [Binance](https://www.binance.com/) ([*Note for binance users](docs/exchanges.md#blacklists))
 - [X] [Kraken](https://kraken.com/)
-- [ ] [113 others to tests](https://github.com/ccxt/ccxt/). _(We cannot guarantee they will work)_
+- [X] [FTX](https://ftx.com)
+- [ ] [potentially many others](https://github.com/ccxt/ccxt/). _(We cannot guarantee they will work)_
+
+### Community tested
+
+Exchanges confirmed working by the community:
+
+- [X] [Bitvavo](https://bitvavo.com/)
 
 ## Documentation