v0.25.0

• Redesigned Zed's light and dark themes. This change was accompanied by some major internal changes to Zed's theming system, which will enable us to more easily iterate on Zed's appearance in the future.
• Added the ability to scroll the tab bar when a pane's tabs overflow.
• Fixed handling of the tab_size setting so that it is properly respected when editing and and when reformatting files on save.
• Simplified the behavior of the alt-enter key bindings in multi-buffer editors, so that files are opened in the currently-active pane.
• Fixed a bug where breadcrumbs would sometimes fail to update in the project diagnostics view.
• Fixed a bug introduced in 0.24 where the app would become unresponsive while a language server was starting up.
• Fixed a bug where diagnostics would sometimes fail to update after restarting a language server with cmd-f10.