add seer + discourse article (#39)

* add seer + discourse article

* contributors subsection

README.md

@@ -183,6 +183,13 @@ The Fivetran team maintaining this package _only_ maintains the latest version o
 ### Contributions
 A small team of analytics engineers at Fivetran develops these dbt packages. However, the packages are made better by community contributions.
 
+We highly encourage and welcome contributions to this package. Check out [this dbt Discourse article](https://discourse.getdbt.com/t/contributing-to-a-dbt-package/657) on the best workflow for contributing to a package.
+
+#### Contributors
+We thank [everyone](https://github.com/fivetran/dbt_linkedin/graphs/contributors) who has taken the time to contribute. Each PR, bug report, and feature request has made this package better and is truly appreciated.
+
+A special thank you to [Seer Interactive](https://www.seerinteractive.com/?utm_campaign=Fivetran%20%7C%20Models&utm_source=Fivetran&utm_medium=Fivetran%20Documentation), who we closely collaborated with to introduce native conversion support to our Ad packages.
+
 ## Are there any resources available?
 - If you have questions or want to reach out for help, see the [GitHub Issue](https://github.com/fivetran/dbt_linkedin/issues/new/choose) section to find the right avenue of support for you.
 - If you would like to provide feedback to the dbt package team at Fivetran or would like to request a new dbt package, fill out our [Feedback Form](https://www.surveymonkey.com/r/DQ7K7WW).