Update README.md (#3174)

Tweaks that weren't picked up in https://github.com/graphql/graphiql/pull/3127/files

packages/cm6-graphql/README.md

@@ -5,7 +5,7 @@
 [![License](https://img.shields.io/npm/l/cm6-graphql.svg?style=flat-square)](LICENSE)
 [Discord Channel](https://discord.gg/cffZwk8NJW)
 
-Provides CodeMirror 6 extension with a parser mode for GraphQL along with a
+Provides CodeMirror 6 extension with a parser mode for GraphQL along with
 autocomplete and linting powered by your GraphQL Schema.
 
 ### Getting Started
@@ -15,8 +15,8 @@ npm install --save cm6-graphql
 ```
 
 [CodeMirror 6](https://codemirror.net/) customization is done through
-[extensions](https://codemirror.net/docs/guide/#extension). This package an
-extension that customizes codemirror 6 for GraphQL.
+[extensions](https://codemirror.net/docs/guide/#extension). This package is
+an extension that customizes CodeMirror 6 for GraphQL.
 
 ```js
 import { basicSetup, EditorView } from 'codemirror';
@@ -31,16 +31,16 @@ const view = new EditorView({
 });
 ```
 
-Note: You have to provide a theme to CodeMirror 6 for the styling you want. You
+_**Note:** You have to provide a theme to CodeMirror 6 for the styling you want. You
 can take a look at
 [this example](https://github.com/graphql/graphiql/blob/main/examples/cm6-graphql-parcel/src/index.ts)
 or see the CodeMirror 6
 [documentation examples](https://codemirror.net/examples/styling/) for more
-details.
+details._
 
 ### Updating schema
 
-If you need to update the GraphQL schema used in the editor dynamically, you can
+If you need to dynamically update the GraphQL schema used in the editor, you can
 call `updateSchema` with the CodeMirror `EditorView` instance and the new schema
 
 ```js