v1.2.0 SDE Update improvements, last big update for a while

Big progress in making the sheet much more user-friendly and suitable for long-term usage.

The instructions are now far more simple to follow (with buttons!) and the UI is more dummy-proof in that cells not intended to be interacted with are locked and the math sheets are hidden.

In terms of replicating EVEMarketer, I consider this project 95% finished. At this point, all there is to do are some minor UI and formatting changes, as well as updating invTypes every so often, but the bulk of the math and logic should be stable for the foreseeable future. There's also a lack of interest in this project, so until I see some sudden interest popping up, I might consider sunsetting ExcelMarketer for now. Thanks for checking this out!

Changes:

SDE Import Improvements

• The sheet now has the functionality to update its SDE sheet by checking if invTypes.csv is in the same folder as the sheet
• Added 2 scripts that both do this update: One upon startup, and one upon clicking a button in the instructions sheet
• Updated the instructions tab to reflect this change

Other minor changes

• Fixed skills to allow untrained/level 0 option
• Minor UI changes