Introducing dark mode

Octopus Deploy 2020.1 introduced a dark mode feature to enhance the user experience by catering to the preferences of developers and operations professionals who often favor this mode for its eye comfort benefits. This update aligns with the company's commitment to maintaining a modern and user-friendly interface, which is crucial for appealing to its developer-centric audience. The implementation involved using CSS custom properties and React Context to manage theming, ensuring a seamless transition between light and dark modes, and leveraging the prefers-color-scheme media feature to detect system settings. Despite challenges with IE11 compatibility, a ponyfill was utilized to ensure basic functionality in that browser. This move reflects Octopus Deploy's focus on design and accessibility, aiming to make software deployment a more enjoyable task.