Add cuchi/jinja2-action

That seems like the first action which uses a template engine. I think it should go under the **Utility** section.

README.md

@@ -172,6 +172,7 @@ Set up your GitHub Actions workflow with a specific version of your programming
 - [Build Slate documentation](https://github.com/Decathlon/slate-builder-action)
 - [Read Properties](https://github.com/christian-draeger/read-properties) - Read values from `.properties` files.
 - [Write Properties](https://github.com/christian-draeger/write-properties) - Write values to `.properties` files.
+- [Apply templates with Jinja2](https://github.com/cuchi/jinja2-action) - Use the Jinja2 template engine to generate files from templates.
 
 #### Environments