revise readme

Author: jcupitt

README.md

@@ -1,25 +1,24 @@
 # nip4 --- a user interface for libvips
 
-**Work in progress** See screenshots and videos below for the current state.
-I'm hoping this will be mostly working in early 2025.
-
 This is a reworking of [nip2](https://github.com/libvips/nip2) for the gtk4
 UI toolkit and the vips8 image processing library.
 
 There's a news post on libvips.org with an introduction:
 
+https://www.libvips.org/2025/03/20/introduction-to-nip4.html
+
+If you used nip2, there's another post outlining the main changes in the
+new interface:
+
 https://www.libvips.org/2025/03/12/nip4-for-nip2-users.html
 
 nip4 is a spreadsheet-like interface to the [libvips image processing
 library](https://libvips.github.io/libvips). You create a set of formula
 connecting your objects together, and on a change nip4 will recalculate.
-This makes it convenient for developing image processing systems since you
-can watch pixels change as you adjust your equations.
-
-Because nip4 uses libvips as the image processing engine, it can handle very
-large images and only needs a little memory. It scales to fairly complex
-workflows: I've used it to develop systems with more than 10,000 cells,
-analyzing images of many tens of gigabytes.
+Because nip4 uses libvips as the image processing engine it can handle
+very large images, recalculates quickly, and only needs a little memory.
+It scales to fairly complex workflows: I've used it to develop systems with
+more than 10,000 cells, analyzing images of many tens of gigabytes.
 
 It has a batch mode, so you can run any image processing system you develop
 from the command-line and without a GUI.
@@ -28,8 +27,6 @@ from the command-line and without a GUI.
 
 [![Screenshot](images/shot2.png)](images/shot2.png)
 
-https://github.com/user-attachments/assets/6f7bdee1-183c-4554-9701-e0c30e75d58a
-
 # Installing
 
 ## Windows