Update pull request checklist to align with updated contribution requirements (i.e. for black, flake8, ./setup.sh and ./test.sh)

[joehiggi1758]

The current checklist for opening a pull request conflicts with the contributing guide. The contributing guide is as follows...

While the pull request checklist is as follows...

# Pull Request Checklist

Below is a simple checklist but please do not hesitate to ask for assistance!

- [x] Fork, clone, and checkout the newest version of the code
- [x] Create a new branch
- [x] Make necessary code changes
- [x] Install `black` (i.e., `python -m pip install black` or `conda install -c conda-forge black`)
- [x] Install `flake8` (i.e., `python -m pip install flake8` or `conda install -c conda-forge flake8`)
- [x] Install `pytest-cov` (i.e., `python -m pip install pytest-cov` or `conda install -c conda-forge pytest-cov`)
- [x] Run `black .` in the root stumpy directory
- [x] Run `flake8 .` in the root stumpy directory
- [x] Run `./setup.sh && ./test.sh` in the root stumpy directory
- [x] Reference a Github issue (and create one if one doesn't already exist)

The pull request checklist should be updated to reflect recent changes surrounding running black, flake8 and ./setup.sh as well as ./test.sh.

[seanlaw]

@joehiggi1758 Would you like to tackle this as well? I think you will need to update this file:

https://github.com/TDAmeritrade/stumpy/blob/main/docs/pull_request_template.md

I think it would make more sense for it to be:

# Pull Request Checklist

Below is a simple checklist but please do not hesitate to ask for assistance!

- [ ] Fork, clone, and checkout the newest version of the code
- [ ] Create a new branch
- [ ] Run `./setup.sh dev` (or `./conda.sh` for `conda` users) to install all dependencies 
- [ ] Make necessary code changes
- [ ] Run `black --exclude=".*\.ipynb" --extend-exclude=".venv" --diff ./` in the root stumpy directory
- [ ] Run `flake8 --extend-exclude=.venv ./` in the root stumpy directory
- [ ] Run `./setup.sh && ./test.sh` in the root stumpy directory
- [ ] Reference a Github issue (and create one if one doesn't already exist)

It would also be beneficial to see if you had any suggestions for changing/modifying the "Contributing Guide"?

[seanlaw]

Also, in the future, it would be better to avoid pasting an image of code into a comment and, instead, use triple backticks:

```
paste python code in between triple backticks (it is usually the key located to the left of `1`)
```

This makes it easier for others to cut/paste/modify the code that you are sharing

[joehiggi1758]

@seanlaw

• Regarding the image of code: I've updated the original issue raised to reflect this, and will follow that going forward! Thanks for the direction!
• Regarding other updates to the "Contributing Guide": there was one dependency that was required to run tests but wasn't called out in the "Contributing Guide". I'll look into which one it was - because tbh I can't remember off the top of my head
• I'd love to tackle this one - I will give it a crack!