finished the mechanism for setting the language

levels/en_EN/sandbox/empty

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+title = Empty sandbox
+
+[description]
+
+This is an empty sandbox you can play around in.
+
+[setup]

levels/en_EN/sandbox/remote

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+title = Sandbox with a remote
+cards = checkout commit-auto pull fetch push
+
+[description]
+
+Here's a sandbox with a remote! Try pulling, fetching, or pushing!
+
+How can you push tags and branches on a remote? How can you delete them again?
+
+[setup yours]
+
+echo "Line 1" > essay
+git add .
+git commit -m "Initial commit"
+
+git push -u friend main
+
+[setup friend]
+
+git checkout main
+echo "Line 2" >> essay
+git commit -am "Another line"

levels/en_EN/sandbox/sequence

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+empty
+remote
+three-commits

levels/en_EN/sandbox/three-commits

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+title = Sandbox with three commits
+cards = checkout add reset-file checkout-file commit merge rebase
+
+[setup]
+
+echo "You wake up." > you
+git add .
+git commit -m "The beginning"
+
+echo "You drink coffee." >> you
+git commit -am "First things first"
+
+echo "You hear a knock on the door." >> you
+git commit -am "Who's there?"
+
+git branch not_main
+
+[description]
+
+Here's a sandbox you can play around in.
+
+You can use both the playing cards, as well as the terminal. This is a real Git terminal! Fun things to try:
+
+- Make a commit that merges three timelines together at once!
+- Create and delete some tags!
+- Make a timeline that's completely independent of the rest!