Update docs and changelog

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [Unreleased]
 ## Add
 - Add [extend_aspect_ratio](https://docs.imgproxy.net/latest/generating_the_url?id=extend-aspect-ratio) processing option.
+- (pro) Add [advanced smart crop](https://docs.imgproxy.net/latest/configuration?id=smart-crop)
 
 ## [3.13.2] - 2023-02-15
 ### Change

docs/configuration.md

@@ -99,6 +99,7 @@ You can limit allowed source URLs with the following variable:
 **⚠️Warning:** Be careful when using this config to limit source URL hosts, and always add a trailing slash after the host.
 
 ❌ Bad: `http://example.com`
+
 ✅ Good: `http://example.com/`
 
 If the trailing slash is absent, `http://example.com@baddomain.com` would be a permissable URL, however, the request would be made to `baddomain.com`.
@@ -278,6 +279,11 @@ imgproxy Pro can apply an unsharpening mask to your images.
 * `IMGPROXY_UNSHARPENING_WEIGHT`: ![pro](./assets/pro.svg) a floating-point number that defines how neighboring pixels will affect the current pixel. The greater the value, the sharper the image. This value should be greater than zero. Default: `1`
 * `IMGPROXY_UNSHARPENING_DIVIDOR`: ![pro](./assets/pro.svg) a floating-point number that defines the unsharpening strength. The lesser the value, the sharper the image. This value be greater than zero. Default: `24`
 
+## Smart crop
+
+* `IMGPROXY_SMART_CROP_ADVANCED`: ![pro](./assets/pro.svg) when `true`, enables usage of the advanced smart crop method. Advanced smart crop may take more time than regular one, yet it produces better results.
+* `IMGPROXY_SMART_CROP_FACE_DETECTION`: ![pro](./assets/pro.svg) when `true`, adds an additional fast face detection step to smart crop.
+
 ## Object detection
 
 imgproxy can detect objects on the image and use them to perform smart cropping, to blur the detections, or to draw the detections.