Fix example docs links

Author: eddumelendez

docs/examples.md

@@ -2,15 +2,15 @@
 
 Examples of different use cases provided by Testcontainers can be found below:
 
-- [Kafka Cluster with multiple brokers](https://github.com/testcontainers/testcontainers-java/tree/master/examples/kafka-cluster)
-- [Linked containers](https://github.com/testcontainers/testcontainers-java/tree/master/examples/linked-container)
-- [Neo4j](https://github.com/testcontainers/testcontainers-java/tree/master/examples/neo4j-container)
-- [Redis](https://github.com/testcontainers/testcontainers-java/tree/master/examples/redis-backed-cache)
-- [Selenium](https://github.com/testcontainers/testcontainers-java/tree/master/examples/selenium-container)
-- [Selenium Module with Cucumber](https://github.com/testcontainers/testcontainers-java/tree/master/examples/cucumber)
-- [Singleton Container Pattern](https://github.com/testcontainers/testcontainers-java/tree/master/examples/singleton-container)
-- [Solr](https://github.com/testcontainers/testcontainers-java/tree/master/examples/solr-container)
-- [Spring Boot](https://github.com/testcontainers/testcontainers-java/tree/master/examples/spring-boot)
-- [Spring Boot with Kotlin](https://github.com/testcontainers/testcontainers-java/tree/master/examples/spring-boot-kotlin-redis)
-- [TestNG](https://github.com/testcontainers/testcontainers-java/tree/master/examples/redis-backed-cache-testng)
-- [ImmuDb](https://github.com/testcontainers/testcontainers-java/tree/master/examples/immudb)
+- [Kafka Cluster with multiple brokers](https://github.com/testcontainers/testcontainers-java/tree/main/examples/kafka-cluster)
+- [Linked containers](https://github.com/testcontainers/testcontainers-java/tree/main/examples/linked-container)
+- [Neo4j](https://github.com/testcontainers/testcontainers-java/tree/main/examples/neo4j-container)
+- [Redis](https://github.com/testcontainers/testcontainers-java/tree/main/examples/redis-backed-cache)
+- [Selenium](https://github.com/testcontainers/testcontainers-java/tree/main/examples/selenium-container)
+- [Selenium Module with Cucumber](https://github.com/testcontainers/testcontainers-java/tree/main/examples/cucumber)
+- [Singleton Container Pattern](https://github.com/testcontainers/testcontainers-java/tree/main/examples/singleton-container)
+- [Solr](https://github.com/testcontainers/testcontainers-java/tree/main/examples/solr-container)
+- [Spring Boot](https://github.com/testcontainers/testcontainers-java/tree/main/examples/spring-boot)
+- [Spring Boot with Kotlin](https://github.com/testcontainers/testcontainers-java/tree/main/examples/spring-boot-kotlin-redis)
+- [TestNG](https://github.com/testcontainers/testcontainers-java/tree/main/examples/redis-backed-cache-testng)
+- [ImmuDb](https://github.com/testcontainers/testcontainers-java/tree/main/examples/immudb)