Typo fixes in repository documentation (#4674)

CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 0d135b3..5251820 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -18,7 +18,7 @@
 - [Plugin tests](https://github.com/flutter/flutter/wiki/Plugin-Tests), which explains
   the different kinds of tests used for plugins, where to find them, and how to run them.
   As explained in the Flutter guide,
-  [**PRs needs tests**](https://github.com/flutter/flutter/wiki/Tree-hygiene#tests), so
+  [**PRs need tests**](https://github.com/flutter/flutter/wiki/Tree-hygiene#tests), so
   this is critical to read before submitting a PR.
 - [Contributing to Plugins and Packages](https://github.com/flutter/flutter/wiki/Contributing-to-Plugins-and-Packages),
   for more information about how to make PRs for this repository, especially when

README.md

diff --git a/README.md b/README.md
index 8e369c3..30c6a2f 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@
 [platform channels](https://flutter.dev/platform-channels/). You can store
 your plugin source code in any GitHub repository (the present repo is only
 intended for plugins developed by the core Flutter team). Once your plugin
-is ready you can [publish](https://flutter.dev/developing-packages/#publish)
+is ready, you can [publish](https://flutter.dev/developing-packages/#publish) it
 to the [pub repository](https://pub.dev/).
 
 If you wish to contribute a change to any of the existing plugins in this repo,