option to specify columns in config.ini by letter

[raythefourth]

New user here. Upon first time using this app, I got an error about wrong data type in a column. It took me a minute to realize that the column numbering in config.ini is 0-based. While that is typical for a python application, it is unexpected for regular users of spreadsheets (or for me at least). As you know, in spreadsheets, the first row is row 1 (not 0) and the first column is A. So, I propose that the config.ini file allow for the user to specify the columns by letter. Furthermore, the readme could be updated to instruct users to input column letters in the config.ini. The old numeric input could still be accepted, so this would not be a breaking change. Thoughts?

[eprbell]

Thanks for sharing this perspective: the case you're making to improve user friendliness for spreadsheet users is solid. I think it should be done as a non breaking change, as you suggested (i.e. the config file should accept both letters and numbers). I'd be happy to review a PR if you or anybody else wants to do this.