Fix typos and cleanup formatting

PiperOrigin-RevId: 205127566

Author: nshahan

CHANGELOG.md

@@ -53,7 +53,7 @@ users in the Dart package ecosystem.
 * Modify `TextHighlighter` to return separate results for adjacent matches,
   rather than concatenating them into a single result.
 * Migrate to using event tearoffs.
-* Deprecate convenience list for materialDirectives. It has been demonstrated
+* Deprecate convenience list for `materialDirectives`. It has been demonstrated
   that it's use increases code size when only some of the components are being
   used. It is preferable to use only the directives needed for your application
   for improved dart2js tree shaking.

lib/css/mdc_web/README.md

@@ -1,4 +1,4 @@
 The files located here are provided and maintained by the Google material team
 also known as mdc-web. They are included here to make their use easier in
-AngularDart applications. They sourced from a larger set of styles available on
-[GitHub](https://github.com/material-components/material-components-web).
+AngularDart applications. They are taken from a larger set of styles available
+on [GitHub](https://github.com/material-components/material-components-web).