Replace Atom references from README.md (Homebrew#139901)

Atom is a [deprecated app](https://github.blog/2022-06-08-sunsetting-atom/), so using it as an example of installable app through `brew` could be annoying for some users. I replaced it with a similar app name (VS Code).

Also, fixed the `alt` in the GIF, as it is not showing an Atom installation, but Alfred.

README.md

@@ -2,7 +2,7 @@
 
 _“To install, drag this icon…” no more!_
 
-Homebrew Cask extends [Homebrew](https://brew.sh) and brings its elegance, simplicity, and speed to the installation and management of GUI macOS applications such as Atom and Google Chrome.
+Homebrew Cask extends [Homebrew](https://brew.sh) and brings its elegance, simplicity, and speed to the installation and management of GUI macOS applications such as Visual Studio Code and Google Chrome.
 
 We do this by providing a friendly CLI workflow for the administration of macOS applications distributed as binaries.
 
@@ -12,7 +12,7 @@ We do this by providing a friendly CLI workflow for the administration of macOS
 
 To start using Homebrew Cask, you just need [Homebrew](https://brew.sh/) installed.
 
-<img src="https://i.imgur.com/FNNM6WL.gif" width="547" alt="Installing and uninstalling Atom (animated gif)">
+<img src="https://i.imgur.com/FNNM6WL.gif" width="547" alt="Installing and uninstalling Alfred (animated gif)">
 
 Slower, now: