fix: correct model ID in README Quick Start (#211)

Closes #205

Author: Kamilbenkirane

README.md

@@ -51,7 +51,7 @@ import celeste
 text   = await celeste.text.generate("Explain quantum computing", model="claude-opus-4-5")
 image  = await celeste.images.generate("A serene mountain lake at dawn", model="flux-2-pro")
 speech = await celeste.audio.speak("Welcome to the future", model="eleven_v3")
-video  = await celeste.videos.analyze(video_file, prompt="Summarize this clip", model="gemini-3-pro")
+video  = await celeste.videos.analyze(video_file, prompt="Summarize this clip", model="gemini-3-pro-preview")
 embeddings = await celeste.text.embed(["lorep ipsum", "dolor sit amet"], model="gemini-embedding-001")
 ```