docs: Remove commented code

backend/src/api/user.ts

@@ -310,33 +310,6 @@ userRouter.post("/level/:id", async (req: LRequest, res) => {
         // Nothing
     } else {
         // The level is new to the user
-        // Is the new level higher than the "highest" already completed level?
-        // let update = {
-        //     levels: user.levels.concat(id),
-        // };
-        // if (id > Math.max(...user.levels)) {
-        //     // TODO: if (!level)
-        //     const level = await db.collection("levels").findOne({
-        //         level: id,
-        //     });
-
-        //     // Convert the level's vocabulary to SM2 metadata
-        //     let sm2: { [id: number]: ISchedulingData } = {};
-        //     level.vocab.forEach((id: number) => {
-        //         sm2[id] = {
-        //             easiness: 1.3,
-        //             consecutiveCorrectAnswers: 0,
-        //             nextDueDate: Date.parse((new Date()).toString()),
-        //         };
-        //     });
-        //     const newVocabMetadata = Object.assign({}, user.vocabMetadata, sm2);
-
-        //     // Also update the lastLevel attribute
-        //     Object.assign(update, {
-        //         lastLevel: id,
-        //         vocabMetadata: newVocabMetadata,
-        //     });
-        // }
         await db.collection("users").updateOne({
             username: user.username,
         }, {