Support Beancount format

Hello! It was nice chatting with you on IRC!

Again, thank you for this very useful little app!

I wanted to pick up where we left off, discussing support for Beancount format (for reference: https://plaintextaccounting.org/quickref/).

Question is, what is the best way to do that?

A simple way would just be to add a second field, and perhaps an option to wrap things in quotes.

But I'm sure there are other differences. Perhaps the best solution would be to choose which format you would like in a menu, and then you would be presented with different fields to use depending on h/ledger or Beancount.

I know nothing about how your app framework works and which way might be easier for you. And best way to go forward for the app, also.

But as we discussed, Beancount needs potentially 2 fields, Payee and Description. And they need to be wrapped in quotes. And you need a cleared/uncleared marker. So I can work around by entering the following in Description field:

``* "Payee" "Description"``

...but that feels hacky. I mean it works, but...

I dunno, what do you think?

Start by comparing the existing ledger input behavior with the Beancount quick reference linked in the issue. Decide how format selection and Beancount's Payee, Description, quoting, and cleared/uncleared marker should fit the app; done means entering and producing valid Beancount-formatted transactions without the current workaround.

Written by the indexing model from the issue text.