add documentation in appropriate files; apply review comments

Author: altxtech

README.md

@@ -34,14 +34,14 @@ RubyLLM gives you one beautiful API for all of them. Same interface whether you'
 
 ```ruby
 # Just ask questions
-chat = RubyLLM.chat(model: "gemini-2.0-flash")
+chat = RubyLLM.chat
 chat.ask "What's the best way to learn Ruby?"
 ```
 
 ```ruby
 # Analyze any file type
 chat.ask "What's in this image?", with: "ruby_conf.jpg"
-chat.ask "What's happening in this video?", with: "presentation.mp4"
+chat.ask "What's happening in this video?", with: "video.mp4"
 chat.ask "Describe this meeting", with: "meeting.wav"
 chat.ask "Summarize this document", with: "contract.pdf"
 chat.ask "Explain this code", with: "app.rb"

docs/_core_features/chat.md

@@ -148,6 +148,31 @@ response = chat.ask "Compare the user interfaces in these two screenshots.", wit
 puts response.content
 ```
 
+### Working with Videos
+
+You can also analyze video files or URLs with vision-capable models. RubyLLM will automatically detect video files and handle them appropriately.
+
+```ruby
+# Ask about a local video file
+chat = RubyLLM.chat(model: 'gemini-2.0-flash')
+response = chat.ask "What happens in this video?", with: "path/to/demo.mp4"
+puts response.content
+
+# Ask about a video from a URL
+response = chat.ask "Summarize the main events in this video.", with: "https://example.com/demo_video.mp4"
+puts response.content
+
+# Combine videos with other file types
+response = chat.ask "Analyze these files for visual content.", with: ["diagram.png", "demo.mp4", "notes.txt"]
+puts response.content
+```
+
+Notes:
+
+    Supported video formats include .mp4, .mov, .avi, .webm, and others (provider-dependent).
+    Only Google Gemini models currently support video input; check the [Available Models Guide]({% link guides/available-models.md %}) for details.
+    Large video files may be subject to size or duration limits imposed by the provider.
+
 RubyLLM automatically handles image encoding and formatting for each provider's API. Local images are read and encoded as needed, while URLs are passed directly when supported by the provider.
 
 ### Working with Audio
@@ -230,6 +255,7 @@ response = chat.ask "What's in this image?", with: { image: "photo.jpg" }
 
 **Supported file types:**
 - **Images:** .jpg, .jpeg, .png, .gif, .webp, .bmp
+- **Videos:** .mp4, .mov, .avi, .webm
 - **Audio:** .mp3, .wav, .m4a, .ogg, .flac
 - **Documents:** .pdf, .txt, .md, .csv, .json, .xml
 - **Code:** .rb, .py, .js, .html, .css (and many others)