ppmdraw, ppmglobe, pnmmercator: add pages (#15357)

* fix ci

* ppmdraw, ppmglobe, pnmmercator: add pages

* Apply suggestions from code review

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

---------

Co-authored-by: K.B.Dharun Krishna <kbdharunkrishna@gmail.com>

pages/common/ppmdraw.md

@@ -0,0 +1,13 @@
+# ppmdraw
+
+> Draw lines, text and more on a PPM image by executing a script.
+> Documentation on the utilized scripting language can be found by following the link below.
+> More information: <https://netpbm.sourceforge.net/doc/ppmdraw.html>.
+
+- Draw on the specified PPM image by executing the supplied script:
+
+`ppmdraw -script '{{setpos 50 50; text_here "hello!"; }}' {{path/to/image.pnm}} > {{path/to/output.pnm}}`
+
+- Draw on the specified PPM image by executing the script in the specified file:
+
+`ppmdraw -scriptfile {{path/to/script}} {{path/to/image.pnm}} > {{path/to/output.pnm}}`