Prior to this change, the 'Save' action was saving a file to the startup
path (or just showed a File Picker dialog) if a file has been opened
by the Open action or by drag-n-dropping a file to the program.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *