qpdf: add page (#1846)

pages/common/qpdf.md

@@ -0,0 +1,23 @@
+# qpdf
+
+> Versatile PDF transformation software.
+
+- Extract pages 1-3, 5 and 6-10 from a PDF file and save them as another one:
+
+`qpdf --empty --pages {{input.pdf}} {{1-3,5,6-10}} -- {{output.pdf}}`
+
+- Merge (concatenate) a list of PDF files and save the result as another one:
+
+`qpdf --empty --pages {{file1.pdf}} {{1,6-8}} --pages {{file2.pdf}} {{3,4,5}} -- {{output.pdf}}`
+
+- Write each group of n pages to a separate output file with a given filename pattern:
+
+`qpdf --split-pages=n {{input.pdf}} {{out_%d.pdf}}`
+
+- Rotate certain pages of a pdf with a given angle:
+
+`qpdf --rotate={{90:2,4,6}} --rotate={{180:7-8}} {{input.pdf}} {{output.pdf}}`
+
+- Remove the password from a password protected file:
+
+`qpdf --password={{password}} --decrypt {{input.pdf}} {{output.pdf}}`