pbmtox10bm, pbmtoxbm, ppmtoxpm, xbmtopbm, ximtoppm, xpmtoppm: add pages (#11407)

pages/common/pbmtoxbm.md

@@ -0,0 +1,12 @@
+# pbmtoxbm
+
+> Convert a PBM image to a X11 or X10 bitmap.
+> More information: <https://netpbm.sourceforge.net/doc/pbmtoxbm.html>.
+
+- Convert a PPM image to a X11 XBM file:
+
+`pbmtoxbm {{path/to/input_file.pbm}} > {{path/to/output_file.xbm}}`
+
+- Explicitly specify whether an X11 or X10 bitmap should be generated:
+
+`pbmtoxbm -{{x11|x10}} {{path/to/input_file.pbm}} > {{path/to/output_file.xbm}}`