Add .env example

.env.example

@@ -0,0 +1,15 @@
+LLM_PROVIDER=openai
+LLM_MODEL=gpt-4o-mini
+EMBEDDING_MODEL=text-embedding-3-large
+OPENAI_API_KEY=your_api_key_here
+GEMINI_API_KEY=your_gemini_key_here
+CHROMA_PERSIST_DIR=./storage/chroma
+TOP_K=30
+TOP_N_CONTEXT=6
+MAX_TOKENS_COMPLETION=1024
+LANGGRAPH_TRACING=false
+SERVICE_LANG=ru
+SALES_REP_NAME=Команда Консоль.Про
+CHUNK_SIZE=500
+CHUNK_OVERLAP=100
+API_SECRET_KEY=your_secret_key_for_admin_endpoints