Improve documentation and help message

docs/telegram-usage.md

@@ -173,6 +173,7 @@ Shows the current whitelist
 
 Shows the current blacklist.
 If Pair is set, then this pair will be added to the pairlist.
+Also supports multiple pairs, seperated by a space.
 Use `/reload_conf` to reset the blacklist.
 
 > Using blacklist `StaticPairList` with 2 pairs  

freqtrade/rpc/telegram.py

@@ -516,7 +516,8 @@ class Telegram(RPC):
                   "*/stopbuy:* `Stops buying, but handles open trades gracefully` \n" \
                   "*/reload_conf:* `Reload configuration file` \n" \
                   "*/whitelist:* `Show current whitelist` \n" \
-                  "*/blacklist:* `Show current blacklist` \n" \
+                  "*/blacklist [pair]:* `Show current blacklist, or adds one or more pairs " \
+                  "to the blacklist.` \n" \
                   "*/help:* `This help message`\n" \
                   "*/version:* `Show version`"
 

freqtrade/tests/rpc/test_rpc_telegram.py

@@ -1099,7 +1099,6 @@ def test_blacklist_static(default_conf, update, mocker) -> None:
     assert freqtradebot.pairlists.blacklist == ["DOGE/BTC", "HOT/BTC", "ETH/BTC"]
 
 
-
 def test_help_handle(default_conf, update, mocker) -> None:
     patch_coinmarketcap(mocker)
     msg_mock = MagicMock()