I copied your module configuration and found a couple things. It looks like you may be having a character set issue. It may just be an artifact of the copy & paste. But here’s what I found:

You need to use the single quote character around your text values. module: 'newsfeed. I’m not sure what character is in there, but my system didn’t like it. The showSourceTitle and showPublishDate variables are not part of the config: {...} section, so the closed curly brace (}) needs to be moved up 2 lines to just after the closed bracket (]). I think that once you make these changes, you’ll have to bounce the magic mirror process to get the content to show up. I was able to see the module, and received no errors, but the content didn’t load.