Clarify more concisely how concepts relate to each other

[itowlson]

Fixes #59.

[kate-goldenring]

At first glance, i thought this acted almost as a table of contents; however, as it references non-design pages, this should maybe live elsewhere

[rylev]

@itowlson @kate-goldenring should this be rebased/merged or closed?

[kate-goldenring]

I think we should still add this in as a TOC for the design section. This needs to be rebased, filenames updated, and this added to summary.md such that it is the top level for the "Understanding the Component Model" section

[kate-goldenring]

@itowlson can we revisit this and see if we can fit in this glossary? It is a great overview for someone who is learning what WASI, WIT and the component model are. I think the package, world, and interface definitions are already covered in the WIT explainer but having a TLDR of them somewhere (maybe the top of the WIT document) could be helpful.

[kate-goldenring]

@itowlson what are your thoughts on moving this to the Introduction page (almost as a preface to help readers know where to go with these new terms in their lexicon)?

[itowlson]

@kate-goldenring I feel like it might be overwhelming in the intro - create the feeling of "you have to know these before you can read the book" possibly. I am no longer quite sure where it would go though. It could possibly be kludged in on the "why the component model" page, even though it's more "what" than why, perhaps?

[kate-goldenring]

Maybe this should go under the Reference section under a new definitions page?

[ericgregory]

This is a great addition--I think the introduction is the right place for this, since these terms are ultimately critical vocabulary for understanding what follows.