Update prettier (gatsbyjs#22520)

* Update prettier to latest version

* Run 'yarn format' from root of project

* Remove prettier-ignore for nested markdown

* Fix starters

* Fix benchmarks

* Fix examples

* Fix integration-tests

* Update eslint-config-prettier & eslint-plugin-prettier

* Fix linting

* Update all .prettierrc

* Run Prettier on full codebase

* Remove unnecessary .prettierrc & .prettierignore files

* Update Prettier script

* Update snapshots

* Revert snapshot

* Revert "Update Prettier script"

This reverts commit 008eb99

* Update snapshot

* Update docs/blog/2018-08-09-swag-store/index.md

Co-Authored-By: Dima An <dmitriym44@gmail.com>

Co-authored-by: Dima An <dmitriym44@gmail.com>

.babelrc

@@ -1,5 +1,3 @@
 {
-  "presets": [
-    ["babel-preset-gatsby-package"]
-  ]
+  "presets": [["babel-preset-gatsby-package"]]
 }