docs: fix duplicate rembg link in image-processing intro

The rembg paragraph linked the same GitHub URL twice; the model-license link now points at the README's models section, where that claim is stated.

Co-Authored-By: Claude <noreply@anthropic.com>

Author: vinta

website/data/category_intros/image-processing.md

@@ -19,7 +19,7 @@ pyvips builds a pipeline of operations and runs it only when you write the resul
 
 Wand is a [ctypes-based ImageMagick binding](https://docs.wand-py.org/en/latest/), so install ImageMagick's MagickWand library first. Its objects are resources like open files: [use them in a `with` block](https://docs.wand-py.org/en/latest/guide/resource.html) so they get closed. Wand's docs say to [never use Wand directly in an HTTP service](https://docs.wand-py.org/en/latest/guide/security.html) or on any public server. Hand the images to a background worker through a queue, and limit ImageMagick's resources and formats in its `policy.xml`.
 
-rembg runs as a [CLI, a Python library, an HTTP server, or a Docker container](https://github.com/danielgatis/rembg). In code, create a session once with `new_session()` and pass it to each `remove()` call, since `remove` otherwise [starts a new session every call](https://github.com/danielgatis/rembg/blob/main/USAGE.md). The model weights [carry their own licenses](https://github.com/danielgatis/rembg), separate from rembg's MIT license, so check the one you use before you ship it in a commercial product.
+rembg runs as a [CLI, a Python library, an HTTP server, or a Docker container](https://github.com/danielgatis/rembg). In code, create a session once with `new_session()` and pass it to each `remove()` call, since `remove` otherwise [starts a new session every call](https://github.com/danielgatis/rembg/blob/main/USAGE.md). The model weights [carry their own licenses](https://github.com/danielgatis/rembg#models), separate from rembg's MIT license, so check the one you use before you ship it in a commercial product.
 
 thumbor is an HTTP server: you [set the size and crop in the image URL](https://github.com/thumbor/thumbor), and it [detects faces and important features](https://thumbor.readthedocs.io/en/latest/) to crop around them. Set a `SECURITY_KEY` so [every URL is signed](https://thumbor.readthedocs.io/en/latest/security.html) and nobody can tamper with it, and build those URLs in Python with [libthumbor](https://thumbor.readthedocs.io/en/latest/libraries.html). In production, [turn off `ALLOW_UNSAFE_URL`](https://thumbor.readthedocs.io/en/latest/configuration.html) and run [more than one instance](https://thumbor.readthedocs.io/en/latest/hosting.html) behind a load balancer.