Add Vellum to Related Resources Page (#1098)

articles/related_resources.md

@@ -25,6 +25,7 @@ People are writing great tools and papers for improving outputs from GPT. Here a
 - [Prompttools](https://github.com/hegelai/prompttools): Open-source Python tools for testing and evaluating models, vector DBs, and prompts.
 - [Scale Spellbook](https://scale.com/spellbook): A paid product for building, comparing, and shipping language model apps.
 - [Semantic Kernel](https://github.com/microsoft/semantic-kernel): A Python/C#/Java library from Microsoft that supports prompt templating, function chaining, vectorized memory, and intelligent planning.
+- [Vellum](https://www.vellum.ai/): A paid AI product development platform to experiment with, evaluate, and deploy advanced LLM apps. 
 - [Weights & Biases](https://wandb.ai/site/solutions/llmops): A paid product for tracking model training and prompt engineering experiments.
 - [YiVal](https://github.com/YiVal/YiVal): An open-source GenAI-Ops tool for tuning and evaluating prompts, retrieval configurations, and model parameters using customizable datasets, evaluation methods, and evolution strategies.