Add custom page size option when creating documents

[sanderai]

Is your feature request related to a problem? Please describe.
Currently Maroto uses only gofpdf.New to create documents with the few predefined page sizes. (A4, A5, Letter etc.)

Describe the solution you'd like
Use gofpdf.NewCustom to allow custom page sizes. Refactor NewMaroto() to accept custom width and height or create a second method for custom documents.

[johnferchermeli]

If the only modification is change gofpdf.New to gofpdf.NewCustom, I think that is only copy & paste the maroto.NewMaroto() code, naming the new constructor as maroto.NewCustom() and change the parameters and the called gofpdf constructor.

[sanderai]

I actually created a fork already and am testing the custom sizing. Will put up a PR soon!

[johnferchermeli]

Very good :D, thank you.

[sanderai]

I don't know how to update the docs (is it automatic based on example files?) so maybe you can help with that. Otherwise all previous tests still pass and the previous method can be used next to this one.

[johnferchermeli]

The docs doesn't have to be updated in every new feature. I will check your PR today =)

[sanderai]

Thanks for the merge! Is there going to be a release soon as well?

[johnfercher]

Released :D

[sanderai]

Perfect, thank you!