ppmtopjxl, ppmwheel, ppmtoapplevol: add pages (#15355)

* fix ci

* ppmtopjxl, ppmwheel, ppmtoapplevol: add pages

pages/common/ppmwheel.md

@@ -0,0 +1,16 @@
+# ppmwheel
+
+> Generate a PPM image of a color wheel.
+> More information: <https://netpbm.sourceforge.net/doc/ppmwheel.html>.
+
+- Generate a color wheel of type `Ppmcirc`:
+
+`ppmwheel {{diameter}} > {{path/to/output.ppm}}`
+
+- Generate a color wheel of type `Hue-value`:
+
+`ppmwheel -huevalue {{diameter}} > {{path/to/output.ppm}}`
+
+- Generate a color wheel of type `Hue-saturation`:
+
+`ppmwheel -huesaturation {{diameter}} > {{path/to/output.ppm}}`