docs: migrate documentation from Gatsby to MkDocs material

[am29d]

Issue #, if available:

Description of changes:

Due to a rather high time investment for documentation maintenance (read: fight npm ecosystem), we decided to move the documentation to MkDocs material. This pull contains the migration of the content to the MkDocs.

Here is the live preview: https://am29d.github.io/aws-lambda-powertools-python/

The github workflow python_docs.yml contains for now the branch docs/mkdocs to have a live preview in my fork. It will be removed once the PR is approved.

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

Breaking change checklist

RFC issue #:

• Migration process documented
• Implement warnings (if it can live side by side)

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[to-mc]

Great changes! Added some comments inline. Not sure if its just me but the content seems quite squashed in the center of the page, so you need to do a bit of side scrolling for some of the code blocks. Can we add a stylesheet to increase the width of .md-grid?

[heitorlessa]

Great changes! Added some comments inline. Not sure if its just me but the content seems quite squashed in the center of the page, so you need to do a bit of side scrolling for some of the code blocks. Can we add a stylesheet to increase the width of .md-grid?

Same here - Experiment using a max-width between 70rem to 77rem to see how that would look like. You will need an additional CSS and use !important to override the theme.

.md-grid
    max-width: 75rem

I've committed most of @cakepietoast suggestions, so we can spend more time on the larger pieces of content we'll also need to change to best use the content area we have now :)

If you're not comfortable with the CSS pieces, leave that with me - I can also adjust the blockquotes I see on Tom's feedback too.

[heitorlessa]

THANK YOU to everyone who helped us in this migration from Gatsby to MKdocs.. in no particular order

@am29d @michaelbrewer @cakepietoast @Nr18

This should be out today