fixes for locales, improvements, more logging, stub cs translation

locales/cs.json

@@ -0,0 +1,4 @@
+{
+  "welcome_public": "Ahoj",
+  "ping_response": "pong, toto je fedigroups verze {version}"
+}

locales/en.json

@@ -49,7 +49,6 @@
   "cmd_unadmin_ok": "User {user} is no longer a group admin!",
   "cmd_unadmin_fail_already": "No action, user {user} is not a group admin",
 
-
   "mention_prefix": "@{user} ",
   "group_announcement": "**📢Group announcement**\n{message}",
   "ping_response": "pong, this is fedigroups service v{version}"