pamoil, pgmbentley, pgmdeshadow, pgmoil, ppmrainbow, ppmrelief, ppmshadow, ppmshift, ppmspread, ppmtoacad, ppmtobmp, ppmtoicr: add pages (#11433)

pages/common/ppmtoacad.md

@@ -0,0 +1,16 @@
+# ppmtoacad
+
+> Convert a PPM image to an AutoCAD database or slide.
+> More information: <https://netpbm.sourceforge.net/doc/ppmtoacad.html>.
+
+- Convert a PPM image to an AutoCAD slide:
+
+`ppmtoacad {{path/to/file.ppm}} > {{path/to/file.acad}}`
+
+- Convert a PPM image to an AutoCAD binary database import file:
+
+`ppmtoacad -dxb {{path/to/file.ppm}} > {{path/to/file.dxb}}`
+
+- Restrict the colors in the output to 8 RGB shades:
+
+`ppmtoacad -8 {{path/to/file.ppm}} > {{path/to/file.dxb}}`