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 *
and customizable indentation level
An example: cat /proc/net/adapters | jp
Another example: cat /proc/all | jp -i 2 (indents are set to 2 spaces, instead of 4 by default)
