They use a CC BY NC SA license, we use CC BY SA licensing, so our licenses do not allowing porting from one site to another anymore. Any content you personally wrote their can be resubmitted here, but if not, you must write your own version.
If need be, you can use portions of the Wikipedia version as a base and tropify it (add the URL for where you got the information in your edit reasons), but DO NOT copy/paste anything from TV Tropes except your own personal work.
Here's a nice and legal starting point for a Fallout 4 article:
https://allthetropes.org/wiki/Fallout_4
I took the lede from the Wikipedia version, stripped out the WP specific stuff, and trope linked it. I cited the web address of the imported content (you can see how in the page history) to fulfill CC BY SA attribution rules.
If you want, all you have to do is build on it from there. :)
Oh yeah, if you want to add tropes TV Tropes has but we don't, you'll have to make your own version of their trope page using your own resources (basically, write it in your words).
Thanks to their licensing change, we can't simply port over their material anymore, so if you want to fill out our trope collection, you'll have to start from scratch. :(