update readmes

LinkPreviewsBot/README.md

@@ -1,9 +1,47 @@
-# ReactionsInfoBot
+# LinkPreviewsBot
 
-This bot will resend messages with links with all variants of `LinkPreviewOptions`
+A long-polling example that resends text-bearing content with every demonstrated
+`LinkPreviewOptions` variant.
 
-## Launch
+## Behavior
+
+The bot handles every content message. It searches the message's text entities for
+the first plain URL or text-link entity. When one is found, it sends the same text
+and entities to the same chat seven times:
+
+- with link previews disabled;
+- with a large preview above the text;
+- with a large preview below the text;
+- with a small preview above the text;
+- with a small preview below the text;
+- with Telegram's default preview size above the text;
+- with Telegram's default preview size below the text.
+
+The detected URL is selected explicitly for each enabled preview. If the content is
+not text-bearing or contains no URL entity, the bot replies that only content with
+a URL is supported. It defines and registers no commands.
+
+## Setup and permissions
+
+1. Create a bot, obtain its token, and keep the token private.
+2. Start a private chat with it, or add it to a chat where previews should be tested.
+3. Ensure Telegram delivers the relevant content messages and the bot may send
+   messages in that chat.
+
+The example uses no administrator-only methods and does not configure a webhook.
+
+## Run
+
+From the repository root:
 
 ```bash
-../gradlew run --args="BOT_TOKEN"
+./gradlew :LinkPreviewsBot:run --args="BOT_TOKEN"
+```
+
+The first argument is the required bot token. The optional, case-sensitive second
+argument `debug` enables formatted library logging on standard output. Arguments
+after the second are ignored.
+
+```bash
+./gradlew :LinkPreviewsBot:run --args="BOT_TOKEN debug"
 ```