update readmes

ChatAvatarSetter/src/main/kotlin/ChatAvatarSetter.kt

@@ -10,6 +10,15 @@ import dev.inmo.tgbotapi.requests.abstracts.asMultipartFile
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 
+/**
+ * Starts a long-polling bot that uses each incoming photo as the avatar of the chat where it was sent.
+ *
+ * The bot downloads the photo and uploads it with `setChatPhoto`. It replies `Done` when the avatar is updated;
+ * if that API call fails, it logs the exception and replies with an error message. The target must be a
+ * non-private chat where the bot is an administrator allowed to change chat information.
+ *
+ * @param args command-line arguments whose first value is the Bot API token
+ */
 suspend fun main(args: Array<String>) {
     val bot = telegramBot(args.first())