📝 docs: update .env.example with RAG API variables (#3461)

* Update .env.example

* Update .env.example

---------

Co-authored-by: Danny Avila <danacordially@gmail.com>

.env.example

@@ -87,7 +87,6 @@ ANTHROPIC_API_KEY=user_provided
 # Azure      #
 #============#
 
-
 # Note: these variables are DEPRECATED
 # Use the `librechat.yaml` configuration for `azureOpenAI` instead
 # You may also continue to use them if you opt out of using the `librechat.yaml` configuration
@@ -265,7 +264,6 @@ MEILI_NO_ANALYTICS=true
 MEILI_HOST=http://0.0.0.0:7700
 MEILI_MASTER_KEY=DrhYf7zENyR6AlUCKmnz0eYASOQdl6zxH7s7MKFSfFCt
 
-
 #==================================================#
 #          Speech to Text & Text to Speech         #
 #==================================================#
@@ -273,6 +271,16 @@ MEILI_MASTER_KEY=DrhYf7zENyR6AlUCKmnz0eYASOQdl6zxH7s7MKFSfFCt
 STT_API_KEY=
 TTS_API_KEY=
 
+#==================================================#
+#                        RAG                       #
+#==================================================#
+# More info: https://www.librechat.ai/docs/configuration/rag_api
+
+# RAG_OPENAI_BASEURL=
+# RAG_OPENAI_API_KEY=
+# EMBEDDINGS_PROVIDER=openai
+# EMBEDDINGS_MODEL=text-embedding-3-small
+
 #===================================================#
 #                    User System                    #
 #===================================================#