Fix: translation errrors (#940)

* FIX: fix translation error in 2-ui/5-loading/01-onload-ondomcontentloaded/article.md

original text: What happens if we set the DOMContentLoaded handler after the document is loaded?

* FIX: fix translation error in 2-ui/2-events/01-introduction-browser-events/04-move-ball-field/task.md

original text: When the page is scrolled, nothing should break.

* FIX: fix translation error in 5-network/06-fetch-api/article.md

original text: The keepalive option indicates that the request may “outlive” the webpage that initiated it.
"outlive" means live longer than ...

* IMP: translation in 6-data-storage/01-cookie/article.md

original text: 1. A samesite=lax cookie is sent if both of these conditions are true 2.So, what samesite=lax does, is to basically allow the most common “go to URL” operation to have cookies. E.g. opening a website link from notes that satisfy these conditions.