Implemented build-stage changelog render

[Luna-Klatzer]

What type of change does this PR perform?

• Maintenance (Non-breaking change that updates dependencies)
• Info or documentation change (Non-breaking change that updates repo info files (e.g. README.md, CONTRIBUTING.md, etc.) or online documentation)
• Website feature update or docs development changes (Change that changes the design or functionality of the websites or docs)
• Development or internal changes (These changes do not add new features or fix bugs, but update the code in other ways)
• Bug fix (Non-breaking change which fixes an issue)
• New feature (Non-breaking change which adds functionality)
• Breaking change (Major bug fix or feature that would cause existing functionality not to work as expected.)
• Requires a documentation update, as it changes language or compiler behaviour

Summary

Implemented build-stage changelog render, which removes the old broken client-side rendering.

Closes #323

List of Changes

• Added an additional download step for the latest CHANGELOG.md from GitHub in the website rendering process. The file content is then injected into the template changelog.ejs.

Does this PR create new warnings?

None.

Detailed Changelog

None.

Linked issues or PRs

• [Docs] Make the render of the Website Changelog to a static one done before Parcel Deployment #323