Create a JS LST doc

[mike-solomon]

To explain the JS LST types and how they work with J types.

[greg-at-moderne]

Left a few comments.

One thing I noticed that not all JS LST elements are mentioned. Not sure if this doc aims at being an exhaustive reference. If so, they should be added. If it's meant just to indicate the concepts of two "namespaces" like J and JS - then I suggest to add some disclaimer sentence at the top like "Some of the most important JS types are:" or similar.
And if the latter - then some of the JS elements mentioned don't seem so crucial to me - e.g. all these called *Type*.

[mike-solomon]

Thanks for the feedback @greg-at-moderne -- my intention wasn't to provide all LST types but, rather, to just pick the most important ones. I did my best guess at it - but I don't really work with any of this stuff so there's definitely bound to be mistakes 😅

Is every LST type that's really important included in here? Is the main issue that we have 3 Type* LSTs defined that aren't really important?

Either way - I'll make sure to update the doc with a clearer intro that only some of the types are included.

[greg-at-moderne]

Is every LST type that's really important included in here? Is the main issue that we have 3 Type* LSTs defined that aren't really important?

I think it's good to have this "what's new in JS, when you know Java LSTs" document. And if so, there's probably no need to list all JS LST elements.

[greg-at-moderne]

LGTM.
TBH I haven't checked the LST trees in the examples sections in details, but they look good at the first glance.

All in all, I think it's well done.