Split amounts should use '$' for their line code

[teeberg]

I'm trying to generate QIF files to import into GnuCash and found two issues that made this process a little bumpy. This is one of them.

With the current QIF formatting of splits, GnuCash will ignore the splits. Comparing the files that qiffen generates with other example files I found on the internet where GnuCash imports splits correctly, I noticed that qiffen writes split amounts using a line code of T, which is the line code for the amount of the overall transaction. Using a $ line code instead makes it work in GnuCash.

Judging by e.g. https://en.wikipedia.org/wiki/Quicken_Interchange_Format, I think GnuCash is in the right here, and qiffen should in fact be using a line code of $ instead of T.

Hence this PR! :) Let me know if there's anything else you'd like me to do!

[isaacharrisholt]

You're right. This is an oversight on my part, I think. Thanks for bringing it to my attention! The more people we get using this, the more things like this that'll crop up and get fixed.