docs: add preview screenshot and fix flake npmDepsHash

Add app screenshot showing tab bar to README. Update flake.nix
npmDepsHash to match current lockfile.

Author: countgitmick

README.md

@@ -9,6 +9,10 @@ An ad-free, private YouTube desktop app with browser-style tabs.<br>
 Watch YouTube without ads or tracking. Open videos, channels, and searches in tabs — just like a browser.
 </p>
 
+<p align="center">
+ <img alt="FreeTube + Tabs showing multiple open tabs" src="/_icons/preview.png" width=800>
+</p>
+
 <hr>
 
 ## The Problem Everyone Knows About

_icons/preview.png

@@ -22,7 +22,7 @@
 
             src = ./.;
 
-            npmDepsHash = "sha256-zKqErsEKjDPTm0kK1Mk7EN7uVGqsiqpPuHFGmTkHN1g=";
+            npmDepsHash = "sha256-09Y2aA3SWC0Q6SAaNxsmxEBPq7EQqC4X2tWMVhb/Q6M=";
             npmDepsFetcherVersion = 2;
             npmFlags = [ "--legacy-peer-deps" ];
             makeCacheWritable = true;