chore: setup markdown formatting (#3224)

* chore(deps): upgrade prettier to v1.8.2

* chore: setup lint-docs script

* docs: add `<!-- prettier-ignore -->`s

* docs: format docs

* Revert "docs: format docs"

This reverts commit 6dba903987dddc498cb589ca311905f25b6aee53.

* chore(prettierrc): set `--no-prose-wrap`

* docs: format docs

* Revert "docs: format docs"

This reverts commit 139bd744b6921916be8fac4fa3bab83bae5d12df.

* docs: tweak

* docs: format docs

* chore: rename .prettierrc

* chore: rename back to .prettierrc

* chore: split out third-party

* refactor: fix linting

* chore: do not split out third-party on website

.prettierrc

@@ -0,0 +1,3 @@
+{
+  "proseWrap": false
+}