cjxl: add more examples, improve description (#23003)

Co-authored-by: Ivan Baluta <ivanbaluta.dev@gmail.com>
Co-authored-by: Managor <42655600+Managor@users.noreply.github.com>

Author: 3 people

pages/common/cjxl.md

@@ -1,16 +1,24 @@
 # cjxl
 
-> Compress images to JPEG XL.
+> Convert and compress images to JPEG XL.
 > Accepted input extensions are PNG, APNG, GIF, JPEG, EXR, PPM, PFM, PAM, PGX, and JXL.
 > More information: <https://github.com/libjxl/libjxl/blob/main/doc/man/cjxl.txt>.
 
 - Convert an image to JPEG XL:
 
-`cjxl {{path/to/image.ext}} {{path/to/output.jxl}}`
+`cjxl {{path/to/image.ext}} {{path/to/output}}.jxl`
 
-- Set quality to lossless and maximize compression of the resulting image:
+- Convert with a specific effort level ('1' - fastest but worst results, '10' - slowest but best results, '7' - default):
 
-`cjxl --distance 0 --effort 9 {{path/to/image.ext}} {{path/to/output.jxl}}`
+`cjxl {{[-e|--effort]}} {{1..10}} {{path/to/image.ext}} {{path/to/output}}.jxl`
+
+- Convert with a specific quality:
+
+`cjxl {{[-q|--quality]}} {{0..100}} {{path/to/image.ext}} {{path/to/output}}.jxl`
+
+- Convert a JPEG to a JPEG XL with specific lossy quality:
+
+`cjxl {{[-q|--quality]}} {{0..100}} {{[-j|--lossless_jpeg]}} 0 {{path/to/image.jpeg}} {{path/to/output}}.jxl`
 
 - Display an extremely detailed help: