docs: document new Scribe Slack app features

- Add eyes emoji reaction feedback when Scribe reads messages
- Document image/multimodal attachment support
- Document Slack thread context unfurling
- Note that PRs are opened by fern-support for white-labeling

Co-Authored-By: Fern Support <info@buildwithfern.com>

Author: fern-support

fern/products/ask-fern/pages/features/scribe-slack-app.mdx

@@ -47,11 +47,18 @@ Once you've installed it in your workspace, add the bot to Slack channels where
 
 ## Usage
 
-Tag `@Scribe` in any channel where it has been added to request documentation changes. Scribe will analyze your request and create a pull request to your connected GitHub repository.
+Tag `@Scribe` in any channel where it has been added to request documentation changes. Scribe reacts with an :eyes: emoji to confirm it has read your message, then analyzes your request and creates a pull request to your connected GitHub repository. Pull requests are opened by `fern-support` to maintain consistent attribution.
 
 Example requests:
 - `@Scribe add a section about authentication to the getting started guide`
 - `@Scribe update the API reference to include the new /plants endpoint`
 - `@Scribe fix the typo in the installation instructions`
 
 Scribe will respond in the thread with a link to the pull request it created.
+
+## Features
+
+Scribe supports several input types to help provide context for your documentation requests:
+
+- **Image attachments**: Include screenshots, diagrams, or other images in your message. Scribe uploads these attachments to the editing session and can reference them when making documentation changes.
+- **Thread context**: When you tag Scribe in a thread, it unfurls the thread history to understand the full context of the conversation before generating changes.