Fix readme dark mode (#189)

Author: digitaldirk

README.md

@@ -1,4 +1,5 @@
-# ![MudBlazor](content/MudBlazor-GitHub-NoBg.png)
+# ![MudBlazor Logo](content/MudBlazor-GitHub-NoBg-Dark.png)
+
 # TryMudBlazor
 [![GitHub](https://img.shields.io/github/license/mudblazor/trymudblazor?color=594ae2&logo=github&style=flat-square)](https://github.com/MudBlazor/TryMudBlazor/blob/main/LICENSE)
 [![Discord](https://img.shields.io/discord/786656789310865418?color=%237289da&label=Discord&logo=discord&logoColor=%237289da&style=flat-square)](https://discord.gg/mudblazor)