You can do this from batch files using ImageMagick or you can do this in a completely automatic manner with Python & PIL/Pillow.
In ImageMagick you can add text to just about any image and output a new image so taking the list of titles and creating a batch file from it that adds the text to the original image and outputs as a new name is quite simple, (personally I would use a python script to generate the batch file from the text list but there are many editors that can use macros to do this sort of job).
The Python + Pillow mechanism is a lot more expandable in that you could use the python some additional python libraries to actually create the list of headlines from the web site automatically and to post the images to the web site for you.
All of the above software is:
- Free, gratis & open source
- Cross platform running on Windows, Linux & OS-X at minimum.