Update TOML file with more description matching README (#2409)

Author: joecummings

pyproject.toml

@@ -1,14 +1,14 @@
 # ---- All project specifications ---- #
 [project]
 name = "torchtune"
-description = "A native-PyTorch library for LLM fine-tuning"
+description = "PyTorch native post-training library"
 readme = "README.md"
 requires-python = ">=3.9"
 license = {file = "LICENSE"}
 authors = [
     { name = "PyTorch Team", email = "[email protected]" },
 ]
-keywords = ["pytorch", "finetuning", "llm"]
+keywords = ["pytorch", "post-training", "rlhf", "finetuning", "llm"]
 dependencies = [
 
     # Hugging Face integrations