Add mention of library.json and module.json (#71)
Add mention of library.json and module.json (#71)

* Add mention of library.json and module.json

Add mention of these two other library manifest formats to the creating a library page.

* Another reference to other library manifest formats

Additional reference to library.properties and module.json further down the page

* Missed a `:`

* Refer to generic manifest rather than specific file

platformio/platformio-docs,platformio/platformio-docs