replace two space syntax with <br> tag (facebook#1393)

for consistency :)

README.md

@@ -82,7 +82,7 @@ You will see the build errors and lint warnings in the console.
 
 ### `npm test`
 
-Runs the test watcher in an interactive mode.  
+Runs the test watcher in an interactive mode.<br>
 By default, runs tests related to files changes since the last commit.
 
 [Read more about testing.](https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/template/README.md#running-tests)
@@ -205,7 +205,7 @@ We are grateful to the authors of existing related projects for their ideas and
 
 ## Alternatives
 
-If you don’t agree with the choices made in this project, you might want to explore alternatives with different tradeoffs.  
+If you don’t agree with the choices made in this project, you might want to explore alternatives with different tradeoffs.<br>
 Some of the more popular and actively maintained ones are:
 
 * [insin/nwb](https://github.com/insin/nwb)