Request for 'STATEMENT' paper size

[lindes]

Perhaps this needs to happen in ruby-pdf, but I couldn't find that on github, so filing here:

It would be nice if PDF::Core::PageGeometry could have a 'STATEMENT' size added for 5.5x8.5-inch paper, i.e. 396.0x612.0 pts.

This is one of several possible names (Memo, Statement, Mini, Invoice, Stationary, Half Letter) for this size, as documented on wikipedia. I'd be fine with most of these names, though I'd advise against using Stationary, and I specifically chose Statement based on a web search for 5.5x8.5" size names, which lists 'Statement' for this size, and lists 'Stationary' as 8x10" instead.

There may be room for other sizes to be added, as well, based on other sizes in the table on that page (or the above definition of 'Stationary').

This is a low-urgency request; I know I can work around it by just specifying an array of point sizes. I just thought it would be a useful addition, so filing an issue to track or reject the idea. (I'd submit a PR, but it seems like the file may be generated, and I don't currently have the energy to track down figuring that out.)

Thanks for considering!