gotenberg/pkg/modules/pdfengines/README.md

Adding PDF Engine Features

When adding a new PDF engine capability (e.g., bookmarks, watermark, stamp, embed), you must update the Makefile to include the corresponding engine list variable and flag. Every --pdfengines-*-engines flag registered in pkg/modules/pdfengines/pdfengines.go must have a matching entry in the Makefile:

1. Add a variable in the Makefile's variable block (around line 60-70):

   PDFENGINES_<FEATURE>_ENGINES=<default engines>
   

2. Add the flag in the Makefile's command args block (around line 140-155):

   --pdfengines-<feature>-engines=$(PDFENGINES_<FEATURE>_ENGINES) \
   

The default value should match what is defined in pdfengines.go's fs.StringSlice(...) call for that flag.