chore: add env example placeholders

Author: GangGreenTemperTatum

.env.example

@@ -5,8 +5,9 @@ DREADNODE_API_KEY=YOUR_DREADNODE_API_KEY
 DREADNODE_LOCAL_DIR="runs/"
 LOGFIRE_IGNORE_NO_CONFIG=1
 
-ANTHROPIC_API_KEY=
-GROQ_API_KEY=
-OPENAI_API_KEY=
-TOGETHER_AI_API_KEY=
-GEMINI_API_KEY=
+# AI provider API keys (replace <ADD_API_KEY> with your actual key)
+ANTHROPIC_API_KEY=<ADD_API_KEY>
+GROQ_API_KEY=<ADD_API_KEY>
+OPENAI_API_KEY=<ADD_API_KEY>
+TOGETHER_AI_API_KEY=<ADD_API_KEY>
+GEMINI_API_KEY=<ADD_API_KEY>