Add a warning on missing pages in pdfly cat

[Lucas-C]

We want to produce a warning (on stderr) when a user attemps to use pdfly cat
to extract a range of pages that is outside the number of pages of the PDF document processed.

We already have a unit test regarding this, so this feature could considered DONE when this unit test will pass:
https://github.com/py-pdf/pdfly/blob/main/tests/test_extract_images.py#L20

[pavankalyan224847]

hello i would like to work on this issue can you please assign it to me

[Lucas-C]

hello i would like to work on this issue can you please assign it to me

Great! Sure, I just did so 🙂

Do you plan to work on this as part of https://hacktoberfest.com?

Also please tell us if you stop working on this, so that we can unassign this issue.

[pavankalyan224847]

Thank you for assigning me this issue and yes i want to work on this as a part of https://hacktoberfest.com

[Lucas-C]

Hi @pavankalyan224847

Are you still planning to work on this, or can we unassign you?

[pavankalyan224847]

please unassign this issue i'll comeback later