Aib improve contributing guidance

[amaiaita]

Description

❓What: improving documentation on contributing to the DS website

🧠Why?: currently it requires me to go through it with new people contributing.

👨‍💻How?:

Checklist:

Have checked for the following:

• The website still builds correctly, and you can view it using mkdocs serve.
• There are no new "warnings" from mkdocs
• Does your page follow the page template (or here in Markdown)? (need to make a new one specific to NHSE Data Science)
• Spelling errors
• Consistent capitalization
• Consistent numbers
• Material features incorrectly implemented: search for code blocks and markers (e.g. !!!).
• Code snippets don't work
• Images not working
• Links not working

Where it was tested

• Github Codespaces - 2-core, 4GB RAM, 32GB hard drive
• devcontainer.json describes further settings

[warren-davies4]

[amaiaita]

@all-contributors add @warren-davies4 for review

[allcontributors]

@amaiaita

@warren-davies4 already contributed before to review

[amaiaita]

@all-contributors add @amaiaita for doc

[allcontributors]

@amaiaita

I've put up a pull request to add @amaiaita! 🎉