Suggestion: rename IU (the code for the new unified IJ IDE) to IJ #2028
Description
Since the announce of the new unified IJ IDE, I see here and there plugin developers asking how to stay compatible with older IDEs and, mostly, IntelliJ Community (IC). They think they will be forced to drop IC compatibility. Others think they should branch their plugin, just for 253+...
From my point of view, this confusion comes from the IU code.
I know the new unified IDE is technically IntelliJ Ultimate, and we can use it without a license. Meanwhile, in the history, IntelliJ Ultimate also refers to a paid IDE.
I won't suggest anything about the IDE name (this is not the right place for that), but I think this would be less confusing for plugin developers if they were invited to switch to a new IDE code when targeting an IDE: IJ. IJ means IntelliJ, and this is exactly what the new unified IntelliJ is.
At least, you could add the IJ code as an alias to IU for 253+ IDEs, and maybe, mention IJ instead of IU in the documentation, hints, etc (again, for 253+ IDEs).?