Add `is.element()` to is-type module
Add `is.element()` to is-type module

Added a new method to the `./src/shared/is-type.js` module which can be
used to identify DOM elements. This method is also available via the
`is.not` object.

ericcornelissen/html-area,ericcornelissen/htmlarea,ericcornelissen/htmlarea