Docs: Add unbound function note on mocha rerun section. (#4846)
Docs: Add unbound function note on mocha rerun section. (#4846)

* Add unbound function note on mocha rerun.

* Specify unbound function necessity scope.

Also removing an erroneous example introduction.

webdriverio/webdriverio,webdriverio/webdriverio,webdriverio/webdriverio