Since I keep seeing that post over and over again on my dash:
No, the Korean Peninsula is not at peace yet.
Nothing has been signed, they have started talks.
This is something they have done before without a resolution being reached, so while it is super hopeful, it isn’t yet a sure thing that the war is going to end.
Here are some sources, because you can’t just say things and make them true:
https://www.nytimes.com/2018/04/27/world/asia/north-korea-south-border.html
https://www.nytimes.com/2018/04/27/world/asia/koreans-set-the-table-for-a-deal-that-trump-will-try-to-close.html
https://www.nytimes.com/2018/04/27/world/asia/north-korea-south-kim-jong-un.html
https://www.nytimes.com/2018/04/27/opinion/sunday/north-korea-south-kim-jong-un.html