[WIP] Add option to invert web colours for better readability

[Copilot]

Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.

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This section details on the original issue you should resolve

<issue_title>I want a option to invert the web colours.</issue_title>
<issue_description>---
title: I want a option to invert the web colours.
date: 2023-10-31T19:12:44.434Z
submitter: Diego Martín Álvarez
number: 654151ac300130006b970a59
tags: [ ]
discussion: https://github.com/WebWeWant/webwewant.fyi/discussions/
status: [ discussing || in-progress || complete ]
related:

• title:
  url:
  type: [ article || explainer || draft || spec || note || discussion ]

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I like to have the possibility of invert the colours of the web that I have active in my web browser.
it Will be very useful have a rapid icon to invert the colours of the visualized web, specially in order to read little black words over white backgrounds.
There is a lot of possibles applications: more easy to read, care our eyes, help people with seight problems or elderys, energy saving, etc.

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If posted, this will appear at https://webwewant.fyi/wants/654151ac300130006b970a59/</issue_description>

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