Boolean query examples

[msfroh]

Before getting into more specialized queries, we really need an explanation of BooleanQuery and some of the basic concepts, like leap-frogging.

[msfroh]

We could actually write a couple of examples -- a high-level example explaining how to use BooleanQuery and a lower-level example explaining how it works.

The high-level example can walk through what the various Occur values mean, for example.

[msfroh]

I wrote a couple of examples:

1. Boolean query intro: cb1fba6
2. Boolean AND query deep-dive: 1778b0e

A similar example diving into OR queries may be helpful.

A more advanced example could look at how impacts are used to skip non-competitive blocks.

[Vikasht34]

@msfroh Could you please assign this to me.