Update README note

Make it clearer that the extension pack includes Sorbet that's
conditionally activated. Also that the debugger extension is on its way
out.

README.md

@@ -10,8 +10,9 @@ This extension pack contains an opinionated collection of pre-configured extensi
 
 - [Ruby LSP](https://marketplace.visualstudio.com/items?itemName=Shopify.ruby-lsp)
 - [VSCode rdbg Ruby Debugger](https://marketplace.visualstudio.com/items?itemName=koichisasada.vscode-rdbg)
+- [Ruby Sorbet](https://marketplace.visualstudio.com/items?itemName=sorbet.sorbet-vscode-extension)
 
-Notice that [Ruby Sorbet](https://marketplace.visualstudio.com/items?itemName=sorbet.sorbet-vscode-extension) will only be activated if your project is onboarded to the [Sorbet type checker](https://sorbet.org/). Otherwise, the extension is never activated.
+Note that the Sorbet extension will only be activated if your project is onboarded to the [Sorbet type checker](https://sorbet.org/). Also, the Ruby Debugger extension is being gradually phased out by the Ruby LSP's debugger. For now, you may need to use rdbg for certain debugging use-cases.
 
 ## Usage