magick: add page (#3653)

pages/common/magick.md

@@ -0,0 +1,24 @@
+# ImageMagick
+
+> Create, edit, compose, or convert bitmap images.
+> More information: <https://imagemagick.org/>.
+
+- Convert file type:
+
+`magick {{image.png}} {{image.jpg}}`
+
+- Resize an image, making a new copy:
+
+`magick convert -resize {{100x100}} {{image.jpg}} {{image.jpg}}`
+
+- Create a GIF using images:
+
+`magick {{*.jpg}} {{images.gif}}`
+
+- Create checkerboard pattern:
+
+`magick -size {{640x480}} pattern:checkerboard {{checkerboard.png}}`
+
+- Convert images to individual PDF pages:
+
+`magick {{*.jpg}} +adjoin {{page-%d.pdf}}`