docs(Readme): reflect that LazyVim For Ambitious Developers is complete (#4407)

## Description

LazyVim for Ambitious Developers is completely released online, with
ebooks available and print edition coming shortly. This just updates the
links to remove the "is working on" wording.

## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

README.md

@@ -115,7 +115,7 @@ There's a great video created by [@elijahmanor](https://github.com/elijahmanor)
 
 [![Watch the video](https://img.youtube.com/vi/N93cTbtLCIM/hqdefault.jpg)](https://www.youtube.com/watch?v=N93cTbtLCIM)
 
-[@dusty-phillips](https://github.com/dusty-phillips) is working on a book called
+[@dusty-phillips](https://github.com/dusty-phillips) wrote a comprehensive book called
 [LazyVim for Ambitious Developers](https://lazyvim-ambitious-devs.phillips.codes)
 available for free online.