Add external blog/video links (#68)

Author: rmoff

README.md

@@ -119,6 +119,9 @@ com.github.jcustenborder.kafka.connect.transform.common.ChangeTopicCase
 ```
 
 This transformation is used to change the case of a topic.
+
+[✍️ Example](https://rmoff.net/2020/12/23/twelve-days-of-smt-day-12-community-transformations/#_change_the_topic_case) / [🎥 Video](https://www.youtube.com/watch?v=Z7k_6vGRrkc&t=274s)
+
 ### Tip
 
 This transformation will convert a topic name like 'TOPIC_NAME' to `topicName`, or `topic_name`.
@@ -212,6 +215,10 @@ com.github.jcustenborder.kafka.connect.transform.common.ExtractTimestamp$Value
 ```
 
 This transformation is used to use a field from the input data to override the timestamp for the record.
+
+[✍️ Example](https://rmoff.net/2020/12/23/twelve-days-of-smt-day-12-community-transformations/#_add_the_timestamp_of_a_field_to_the_topic_name) / [🎥 Video](https://www.youtube.com/watch?v=Z7k_6vGRrkc&t=430s)
+
+
 ### Configuration
 
 #### General
@@ -452,6 +459,10 @@ com.github.jcustenborder.kafka.connect.transform.common.TimestampNowField$Value
 ```
 
 This transformation is used to set a field with the current timestamp of the system running the transformation.
+
+[✍️ Example](https://rmoff.net/2020/12/23/twelve-days-of-smt-day-12-community-transformations/#_add_the_current_timestamp_to_the_message_payload) / [🎥 Video](https://www.youtube.com/watch?v=Z7k_6vGRrkc&t=679s)
+
+
 ### Configuration
 
 #### General
@@ -581,4 +592,4 @@ Contributions are always welcomed! Before you start any development please creat
 start a discussion. Create a pull request against your newly created issue and we're happy to see
 if we can merge your pull request. First and foremost any time you're adding code to the code base
 you need to include test coverage. Make sure that you run `mvn clean package` before submitting your
-pull to ensure that all of the tests, checkstyle rules, and the package can be successfully built.
+pull to ensure that all of the tests, checkstyle rules, and the package can be successfully built.