minor edits

exchanges.cfg

@@ -1,6 +1,7 @@
 # -------------------------------------------------------------------------------
 # You can create a custom bundle of CCXT including only the exchanges you need.
-# Add ids below and launch `npm run build`. Empty config will build full library.
+# Add or uncomment ids below and launch `npm run build`.
+# Leaving this config empty will build all exchanges.
 # -------------------------------------------------------------------------------
 
 # binance