Update README.adoc

added contributing guidelines

README.adoc

@@ -81,4 +81,25 @@ You can get `ZonedDateTime` using `RFC5424Timestamp` class:
 ----
 RFC5424Timestamp timestamp = new RFC5424Timestamp(rfc5424Frame.timestamp);
 System.out.println("Current timestamp in ZonedDateTime: " + timestamp.toZonedDateTime());
-----
+----
+
+## Contributing
+
+// Change the repository name in the issues link to match with your project's name
+
+You can involve yourself with our project by https://github.com/teragrep/repo-template/issues/new/choose[opening an issue] or submitting a pull request. 
+
+Contribution requirements:
+
+. *All changes must be accompanied by a new or changed test.* If you think testing is not required in your pull request, include a sufficient explanation as why you think so.
+. Security checks must pass
+. Pull requests must align with the principles and http://www.extremeprogramming.org/values.html[values] of extreme programming.
+. Pull requests must follow the principles of Object Thinking and Elegant Objects (EO).
+
+Read more in our https://github.com/teragrep/teragrep/blob/main/contributing.adoc[Contributing Guideline].
+
+### Contributor License Agreement
+
+Contributors must sign https://github.com/teragrep/teragrep/blob/main/cla.adoc[Teragrep Contributor License Agreement] before a pull request is accepted to organization's repositories. 
+
+You need to submit the CLA only once. After submitting the CLA you can contribute to all Teragrep's repositories.