Fix grammar in README

Author: dsyer

Diff for: README.md

@@ -79,7 +79,7 @@ request but before a merge.
 * Use the Spring Framework code format conventions. Import `eclipse-code-formatter.xml` from the root of the project
   if you are using Eclipse. If using IntelliJ, copy `spring-intellij-code-style.xml` to `~/.IntelliJIdea*/config/codestyles`
   and select spring-intellij-code-style from Settings -> Code Styles.
-* Make sure all new .java files to have a simple Javadoc class comment with at least an @author tag identifying you, and
+* Make sure all new .java files have a simple Javadoc class comment with at least an @author tag identifying you, and
   preferably at least a paragraph on what the class is for.
 * Add the ASF license header comment to all new .java files (copy from existing files in the project)
 * Add yourself as an @author to the .java files that you modify substantially (more than cosmetic changes).