Step 1: Click on Search icon, and search for content as per your requirement

Step 2: you can click on Eye Symbol below image in listing to preview and read the article content to decide if content match to your requirement.

Step3 : Once you decide which content to use to create article you can simply close the popup and click on edit button.

Step 4 : Article Editor UI

Step 5 : When you want to add any content to your article click on "Add to Article". once clicked the content will be added to article editor.

Step 6 : Publish the Article 

Note -: There are Many other advance features are provided by the article editor UI, the getting started section include tutorials for them.