Update feature list icon and refine prompt caching description in README

Author: robertpiosik

README.md

@@ -19,8 +19,8 @@ Code Web Chat is a free and open-source (FOSS), independent AI coding toolkit fo
 - APIs—_[Google](https://aistudio.google.com/api-keys), [OpenAI](https://platform.openai.com/api-keys), [OpenRouter](https://openrouter.ai/settings/keys), [local Ollama](https://ollama.com/search), etc._
 
 ✅ **Apply responses**—interactive multi-file changes integration \
-🔋 **Batteries included**—code completions, commit messages \
-🌱 **Sustainable**—optimized [prompt caching](https://platform.openai.com/docs/guides/prompt-caching) across tasks \
+✅ **Batteries included**—code completions, commit messages \
+🌱 **Sustainable**—optimized for [prompt caching](https://platform.openai.com/docs/guides/prompt-caching) across tasks \
 ✋ **Privacy-first**—strict zero telemetry policy
 
 <p>