Update the build pipeline

[dmint789]

This is a big PR, but this was a very important update for us to make. It should improve the developer experience greatly when it comes to building the PDFs to see a preview of the documents, which was previously only really easy to do by creating a PR and waiting for the Github pipeline to do it, which always took a while and made it harder to iterate with minor adjustments. This PR does the following:

• Update the build script to use weasyprint instead of wkhtmltopdf, which is no longer maintained and causes bugs in the output PDFs sometimes. Some other minor improvements to this script have also been made.
• Add a new build script that uses Docker for consistent file rendering.
• Unify the duplicated styles between the documents and edudoc stylesheets, and keep the directory-specific styles in their own separate files: documents-style.css and edudoc-style.css
• Make minor adjustments to the documents themselves to ensure there are no alignment issues and to make some of the Markdown look cleaner.
• Renumber points 5. and 6. of the WCA Bylaws section 2.4 as 4. and 5. respectively (point 4. was missing). Keep in mind that it's displayed as 1-5 in production rn, because Markdown seems to ignore what number you actually put there and simply uses the correct one in order.