Add Windows installation instructions for Scoop (flameshot-org#4501)

* Add Windows installation instructions for Scoop

* Apply suggestion from @ofek

Author: ofek

README.md

@@ -386,7 +386,7 @@ After following all those steps above, `flameshot` will open without problems in
 
 ### Windows
 
-- [Chocolatey](https://chocolatey.org/packages/flameshot)
+- [Scoop](https://github.com/ScoopInstaller/Extras/blob/master/bucket/flameshot.json): `scoop install flameshot`
 
 <details>
   <summary>Expand this section to see what distros are using an up to date version of flameshot</summary>
@@ -594,4 +594,4 @@ Thanks to sponsors:
 - [Namecheap](https://www.namecheap.com/)
 - [JetBrains](https://www.jetbrains.com/)
 - [SignPath](https://signpath.io/)
-- [addy.io](https://addy.io/)
+- [addy.io](https://addy.io/)