Docs: Improve the documentation for kittens

Add more text roles and links.
Add an example that broadcasts only to other windows in the current tab.
Initial capitalization of the key names in the kbd text role.
Add Python type hints for custom kittens.
Note about hyperlink support for ls on macOS.
Add description text for show_key.

kittens/remote_file/main.py

@@ -55,7 +55,7 @@ The data used to connect over ssh.
 def show_error(msg: str) -> None:
     print(styled(msg, fg='red'))
     print()
-    print('Press any key to exit...')
+    print('Press any key to quit')
     sys.stdout.flush()
     with raw_mode():
         while True:
@@ -208,7 +208,7 @@ def main(args: List[str]) -> Result:
     except SystemExit as e:
         if e.code != 0:
             print(e.args[0])
-            input('Press enter to quit...')
+            input('Press Enter to quit')
         raise SystemExit(e.code)
 
     try:
@@ -236,7 +236,7 @@ def save_as(conn_data: SSHConnectionData, remote_path: str, cli_opts: RemoteFile
         last_used_path = tempfile.gettempdir()
     last_used_file = os.path.join(last_used_path, os.path.basename(remote_path))
     print(
-        'Where do you wish to save the file? Leaving it blank will save it as:',
+        'Where do you want to save the file? Leaving it blank will save it as:',
         styled(last_used_file, fg='yellow')
     )
     print('Relative paths will be resolved from:', styled(os.getcwd(), fg_intense=True, bold=True))