templates: Add rag lantern template (#16523)

Replace this entire comment with:
  - **Description:** Added a template for lantern rag usage.

---------

Co-authored-by: Erick Friis <erick@langchain.dev>

templates/rag-lantern/pyproject.toml

@@ -0,0 +1,39 @@
+[tool.poetry]
+name = "rag-lantern"
+version = "0.1.0"
+description = "RAG using Lantern retriver"
+authors = [
+    "Gustavo Reyes <gustavo@lantern.dev>",
+]
+readme = "README.md"
+
+[tool.poetry.dependencies]
+python = ">=3.8.1,<4.0"
+langchain = "^0.1"
+openai = "<2"
+tiktoken = "^0.5.1"
+rag-lantern = {path = "packages/rag-lantern", develop = true}
+
+[tool.poetry.group.dev.dependencies]
+langchain-cli = ">=0.0.15"
+[tool.poetry.group.dev.dependencies.python-dotenv]
+extras = [
+    "cli",
+]
+version = "^1.0.0"
+
+[tool.langserve]
+export_module = "rag_lantern.chain"
+export_attr = "chain"
+
+[tool.templates-hub]
+use-case = "rag"
+author = "Lantern"
+integrations = ["OpenAI", "Lantern"]
+tags = ["vectordbs"]
+
+[build-system]
+requires = [
+    "poetry-core",
+]
+build-backend = "poetry.core.masonry.api"