Add Cosmic JS Starter (#5916)
Add Cosmic JS Starter (#5916)

* Cosmic JS Gatsby Blog article

* Cosmic JS source plugin link

* fix: miscellaneous edits

- removed an intro to Gatsby, which isn't necessary on the Gatsby blog
- minor cleanup for clarity and grammar
- removed some language that can be problematic for beginners (e.g. "obviously")
- added links to relevant Gatsby concepts and APIs

* rm gatsby image, add config notes

* add canonicalLink

* Update index.md

* cosmicjs starter

* cosmicjs starter copy

* Delete package-lock.json

ChristopherBiscardi/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,0x80/gatsby,gatsbyjs/gatsby,gatsbyjs/gatsby,fk/gatsby,0x80/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,gatsbyjs/gatsby,ChristopherBiscardi/gatsby,mingaldrichgan/gatsby,0x80/gatsby,fk/gatsby,ChristopherBiscardi/gatsby,mingaldrichgan/gatsby,fk/gatsby,mingaldrichgan/gatsby