style: Don't convert single \n to <br> (#3414)

* Update development instructions

* Don't convert single \n to <br>

* Add changeset

* Update .changeset/olive-mice-hide.md

---------

Co-authored-by: Dimitri POSTOLOV <dmytropostolov@gmail.com>

Author: leonardehrenfried

.changeset/olive-mice-hide.md

@@ -0,0 +1,6 @@
+---
+'graphiql': patch
+'@graphiql/react': patch
+---
+
+Respect Markdown format: ignore single newline

packages/graphiql-react/src/markdown.ts

@@ -1,6 +1,8 @@
 import MarkdownIt from 'markdown-it';
 
 export const markdown = new MarkdownIt({
-  breaks: true,
+  // we don't want to convert \n to <br> because in markdown a single newline is not a line break
+  // https://github.com/graphql/graphiql/issues/3155
+  breaks: false,
   linkify: true,
 });