Lowercase the "settings" in "Telegram settings"

Seems to be customary.

Author: lassik

README.md

@@ -29,7 +29,7 @@ Clone this Git repository into `phpBB/ext/lassik/telegramnotifications`:
 In phpBB, go to "ACP" > "Customise" > "Extensions" and enable the
 "Telegram Notifications" extension.
 
-Then to "ACP" > "Extensions" > "Telegram Settings" and fill in the
+Then to "ACP" > "Extensions" > "Telegram settings" and fill in the
 settings. You get the auth token when you make the bot. To get the
 chat ID, try the "Find chat ID" page or from the sidebar or see
 <https://stackoverflow.com/questions/32423837/telegram-bot-how-to-get-a-group-chat-id>.

controller/acp_controller.php

@@ -51,7 +51,7 @@ public function __construct(
 	}
 
 	/**
-	 * Handle the "Telegram Settings" ACP page.
+	 * Handle the "Telegram settings" ACP page.
 	 *
 	 * @param string $u_action
 	 */

language/en/info_acp_namespace.php

@@ -25,7 +25,7 @@
 	'ACP_TELEGRAM_FOUND_CHAT_ID'    => 'Found the following chat ID',
 	'ACP_TELEGRAM_LAST_ERROR'       => 'Last error',
 	'ACP_TELEGRAM_NOTIFICATIONS'    => 'Telegram Notifications',
-	'ACP_TELEGRAM_SETTINGS'         => 'Telegram Settings',
+	'ACP_TELEGRAM_SETTINGS'         => 'Telegram settings',
 	'ACP_TELEGRAM_SETTINGS_UPDATED'	=> 'Telegram settings have been updated',
 	'ACP_TELEGRAM_USE_CHAT_ID'      => 'Use this chat ID',
 ));