May I ask why a text file, and not a database?
I'm curious because a text-file would be highly limited. You would have to submit lines of code into the text file so it could be pulled out and viewed on the web. For example you would have to upload the picture then send the code to either display the picture, or the url to the picture in the text file.
It might work, but would be especially limited when designing the physical look of your site.
Databases are much more secure. You never really want to have info stored in plain text where people can access it.