feat: Introduce BooleanT and boolean functions (#17)

This PR adds a boolean section, as well as an isNaN predicate on numbers. In a TypeDispatcher, when BooleanT is present, isNaN returns a BooleanT. However, in a numbers-only TypeDispatcher, it returns 1 or 0 instead. Moreover, when booleans are subsequently added to a numbers-only instance, isNaN properly reconfigures itself to return BooleanT.

No predicates that depend on approximate equality testing or a configuration object are implemented in this PR.

This PR also implements type matching and dispatching with implicit conversions, and adds an implicit conversion from BooleanT to NumberT.

Reviewed-on: #17
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>

src/generic/__test__/arithmetic.spec.js

@@ -5,7 +5,7 @@ describe('generic arithmetic', () => {
    it('squares anything', () => {
       assert.strictEqual(math.square(7), 49)
       assert.strictEqual(
-         math.square.resolve([math.types.Number]).returns,
-         math.types.Number)
+         math.square.resolve([math.types.NumberT]).returns,
+         math.types.NumberT)
    })
 })