How to show custom static content at top of each category page?

I want to display custom static content, essentially an image and a small description, at the top of each category page (different for each category and sub category), displayed above a list of titles of the category posts with excerpts.

Is there an automated solution/plugin available for this? I need an automated way to insert text/image too because I want to pass this to my content writer and he will take care of the new categories. A rich text editor where I can insert image and text, which will be assigned to a category and can be shown on top of the category page.

Simply call the category_description() – this displays the description that you can enter for each category that you add in the admin UI under “category” (or post tag or each other custom taxonomy).

You can as well use the underlying API function:

term_description( $category, 'category' );