keys: Add SHOW_POLL_VOTES hotkey.

SHOW_POLL_VOTES : 'v' to check votes for a given poll.

Author: rsashank

docs/hotkeys.md

@@ -62,6 +62,7 @@
 |Toggle star status of the current message|<kbd>Ctrl</kbd> + <kbd>s</kbd> / <kbd>*</kbd>|
 |Show/hide message information|<kbd>i</kbd>|
 |Show/hide message sender information|<kbd>u</kbd>|
+|Show/hide poll voter list|<kbd>v</kbd>|
 
 ## Stream list actions
 |Command|Key Combination|

zulipterminal/config/keys.py

@@ -300,6 +300,11 @@ class KeyBinding(TypedDict):
         'help_text': 'Show/hide message sender information',
         'key_category': 'msg_actions',
     },
+    'SHOW_POLL_VOTES': {
+        'keys': ['v'],
+        'help_text': 'Show/hide poll voter list',
+        'key_category': 'msg_actions',
+    },
     'EDIT_HISTORY': {
         'keys': ['e'],
         'help_text': 'Show/hide edit history',