config intellisense

[claytercek]

Took a pass at adding intellisense to config files via the defineConfig method mentioned in #125. This is downstream of #118 and #124.

• narrowed most of the vague types (any, *, {}, and object)
• converted classes to JSDoc type definitions
• added functions to apply defaults to high level configs
• added defineConfig function exported from the core package, as well as a defineContentConfig exported from the content package, and a defineMonitorConfig exported from the monitor package

resolves #125

Intellisense in action here: