Create tech stack docs (techstack.yml and techstack.md)

[stack-file]

Adding tech stack documentation to allow anyone to easily see what is being used in this repo without digging through config files. Two files are being added: techstack.yml and techstack.md. techstack.yml contains data on all the technologies being used in this repo. techstack.md is a visualization of the YML file and displays the tech stack data in a pretty Markdown file.

💡 Protip: techstack.md contains a comment at the top of the file that the following README snippet (with and without the logos) at the top of the file as a comment:

<--- Readme.md Snippet without images Start --->

Tech Stack

buvnswrn/pyRDDLGym is built on the following main stack:

• Python – Languages
• Matplotlib – Charting Libraries
• Pillow – Image Processing and Management
• NumPy – Data Science Tools
• TensorFlow – Machine Learning Tools
• pygame – Game Development

Full tech stack here

<--- Readme.md Snippet without images End --->

Get the code:

## Tech Stack
buvnswrn/pyRDDLGym is built on the following main stack:

- [Python](https://www.python.org) – Languages
- [Matplotlib](http://matplotlib.org) – Charting Libraries
- [Pillow](https://python-pillow.github.io/) – Image Processing and Management
- [NumPy](http://www.numpy.org/) – Data Science Tools
- [TensorFlow](https://www.tensorflow.org) – Machine Learning Tools
- [pygame](https://www.pygame.org/news) – Game Development

Full tech stack [here](/techstack.md)

---

<--- Readme.md Snippet with images Start --->

Tech Stack

buvnswrn/pyRDDLGym is built on the following main stack:

• Python – Languages
• Matplotlib – Charting Libraries
• Pillow – Image Processing and Management
• NumPy – Data Science Tools
• TensorFlow – Machine Learning Tools
• pygame – Game Development

Full tech stack here

<--- Readme.md Snippet with images End --->

Get the code:

## Tech Stack
buvnswrn/pyRDDLGym is built on the following main stack:

- <img width='25' height='25' src='https://img.stackshare.io/service/993/pUBY5pVj.png' alt='Python'/> [Python](https://www.python.org) – Languages
- <img width='25' height='25' src='https://img.stackshare.io/service/2993/2DZC4KaA_400x400.jpg' alt='Matplotlib'/> [Matplotlib](http://matplotlib.org) – Charting Libraries
- <img width='25' height='25' src='https://img.stackshare.io/service/2375/default_1f67b0ca7416a9f52beb655f90b5602d5ef74b75.jpg' alt='Pillow'/> [Pillow](https://python-pillow.github.io/) – Image Processing and Management
- <img width='25' height='25' src='https://img.stackshare.io/service/2179/default_332f874a2edb2686f578aa6389313efcea1eec41.png' alt='NumPy'/> [NumPy](http://www.numpy.org/) – Data Science Tools
- <img width='25' height='25' src='https://img.stackshare.io/service/4717/FtFnqC38_400x400.png' alt='TensorFlow'/> [TensorFlow](https://www.tensorflow.org) – Machine Learning Tools
- <img width='25' height='25' src='https://img.stackshare.io/service/6512/default_1e1ae07154b9f359c410f3f24ba3c96c1be21cdf.jpg' alt='pygame'/> [pygame](https://www.pygame.org/news) – Game Development

Full tech stack [here](/techstack.md)