Markdown News, Message of the Day, Notes and Descriptions

[Alfagun74]

The client should support Markdown for two main use cases:

1. Displaying emphasized descriptions.
2. Rendering a "Message of the Day" (MOTD) and "Phalcode News" page on startup.

Tasks:

Server-side:

• [x] Implement a GET API for /config/news.md, a Markdown file that admins can edit.
• [x] Implement a page for news.md at gamevau.lt/news.md.
• [X] Support Markdown in Descriptions
• [X] Implement a "Notes" field in GameMetadata for Admin notes, that also supports markdown.

Client-side:

• [x] Integrate a Markdown library capable of editing and visualizing Markdown files.
• [x] Render Markdown Description in GameView
• [x] Render Markdown Notes in GameView
• [x] Create a new Newspopup with two tabs: one for server news and one for GameVault news, displaying Markdown content from specified URLs.
• [x] Add a button to re-open the News/MOTD popup.
• [x] Calculate a checksum based on the contents of news.md and news.md. If the user has already seen this checksum, the popup should not auto-open; otherwise, it should open on startup (similar to Steam).

[Alfagun74]

If for some reason anybody should formulate the requirement to turn markdown in descriptions and notes off, we could use this library but for now i think it should always be on.