Fix typo in README (#818)

Co-authored-by: nabil.shafi <nabil-sys@servicemarket.com>

Author: nabilshafi

README.md

@@ -112,7 +112,7 @@ A [checkstyle](https://checkstyle.sourceforge.io/) file is available, and PRs mu
 The project can be built using [Apache Maven](https://maven.apache.org/), such as <code>mvn clean install</code>.
 Continuous Integration takes place using [GitHub Actions](https://github.com/JodaOrg/joda-time/actions).
 Units tests are written in [JUnit](https://junit.org/) and run as part of the build and continuous integration.
-Changes via PR must include appropiate test coverage.
+Changes via PR must include appropriate test coverage.
 
 Note that Joda-Time is considered to be a largely “finished” project. No major enhancements are planned. If using Java SE 8, please migrate to java.time (JSR-310).