Update note about archs of binaries in README

Author: Martchus

README.md

@@ -25,8 +25,8 @@ Issues can be created on GitHub but please read the "[Known bugs and workarounds
 before.
 
 ## Supported platforms
-Official binaries are provided for Windows and GNU/Linux for the x86_64 architecture and can be download from
-the [website](https://martchus.github.io/syncthingtray/#downloads-section) and the
+Official binaries are provided for Windows (for i686, x86_64 and aarch64) and GNU/Linux (for x86_64) and can be
+download from the [website](https://martchus.github.io/syncthingtray/#downloads-section) and the
 [release section on GitHub](https://github.com/Martchus/syncthingtray/releases). This is only a fraction of
 the available downloads, though. I also provide further repositories for some GNU/Linux distributions. There are
 also binaries/repositories provided by other distributors. For a list with links, checkout the