Updating `man l3build` about l3build HOT 7 CLOSED

   ctan         Create CTAN-ready archive
   manifest     Creates a manifest file
   upload       Send archive to CTAN for public release

   --debug                Runs target in debug mode
   --dirty                Skip cleaning up the test area
   --email                Email address of CTAN uploader
   --file|-F              Take the upload announcement from the given file
   --full                 Install all files
   --help|-h              Print this message and exit
   --message|-m           Text for upload announcement message
   --show-log-on-error    Show the full log of the failure with 'halt-on-error'
   --show-saves|-S        Show the invocation to update failing .tlg files
   --version              Print version information and exit

       --pdf|-p
              Check/save PDF files