Include example on adding to existing page

[JasonBarnabe]

All the examples seem to be about adding a new page to a PDF and adding content to it. It would be helpful to have an example of adding content to an existing page. It took me numerous tries before finding something that would work:

      pdf      = Origami::PDF.read(path)
      contents = Origami::ContentStream.new
      contents.write('some text', {
          x: 200,
          y: 200,
      })
      pdf.get_page(1).setContents([pdf.get_page(1).Contents, contents])
      pdf.save(path)

[sudhanshug16]

Hey @JasonBarnabe, I know it has been a long time since you wrote this but it will be great if you can help.
I am trying to do the same and in the output the fields are showing up mirrored for some reason 🤔
Do you know the fix for this?
An example for the same:

cc @gdelugre

Code sample:

pdf = Origami::PDF.read file.path

page_count = pdf.pages.size

page_count.times do |i|
  page = pdf.get_page i + 1
  page.add_font Origami::Font::Type1::Standard::Helvetica.new.pre_build, :Helvetica
  contents = Origami::ContentStream.new
  contents.write("#nice text{i}", {
    x: x,
    y: y,
    font: :Helvetica
  })
  page.setContents([page.Contents, contents])
end

buffer = StringIO.new
pdf.write buffer
buffer.rewind

send_data buffer.string