feat: add Prettier challenge page and related assets

- Introduced a new live view for the Prettier challenge, detailing the competition and prize structure.
- Updated the router to include a new route for the Prettier challenge page.
- Added multiple image assets for the challenge, including background images and sponsor logos.
- Enhanced the overall layout and design of the challenge page to improve user engagement.

Author: zcesur

lib/algora_web/live/challenges/prettier_live.ex

@@ -144,6 +144,7 @@ defmodule AlgoraWeb.Router do
       live "/onboarding/org", Onboarding.OrgLive
       live "/onboarding/dev", Onboarding.DevLive
       live "/pricing", PricingLive
+      live "/challenges/prettier", Challenges.PrettierLive
       live "/swift", SwiftBountiesLive
       live "/blog/:slug", BlogLive, :show
       live "/blog", BlogLive, :index