pbmmake, pgmmake, ppmlabel, ppmmake, ppmmix, ppmntsc, ppmpat: add pages (#11435)

Co-authored-by: Sebastiaan Speck <12570668+sebastiaanspeck@users.noreply.github.com>

pages/common/ppmpat.md

@@ -0,0 +1,12 @@
+# ppmpat
+
+> Produce a PPM image with a pattern.
+> More information: <https://netpbm.sourceforge.net/doc/ppmpat.html>.
+
+- Produce a PPM file of the specified pattern with the specified dimensions:
+
+`ppmpat -{{gingham2|gingham3|madras|tartan|poles|...}} {{width}} {{height}} > {{path/to/file.ppm}}`
+
+- Produce a PPM file of a camo pattern using the specified colors:
+
+`ppmpat -camo -color {{color1,color2,...}} {{width}} {{height}} > {{path/to/file.ppm}}`