First draft of template engine chapter

I've added myself to the table of contributors, but I have a few questions about the information we're choosing to present.
Above, you said: "Dots can be used multiple times on a single value to navigate down an attribute or element chain." Here, we're also calling key/value pairs or array lookups (and other container lookups) "attribute or item access". I actually think a reader new to templates might still be surprised at this stage that the intention could be to look up a dictionary value by key or a list item by index with this syntax; we might want to make this very clear in the initial description.