fix(docs): Fix occ example for dashboard layout

[SystemKeeper]

☑️ Resolves

The occ command for user:setting does not have a --value option:

The "--value" option does not exist.

user:setting [--output [OUTPUT]] [--ignore-missing-user] [--default-value DEFAULT-VALUE] [--update-only] [--delete] [--error-if-not-exists] [--] <uid> [<app> [<key> [<value>]]]

Org. reported at https://help.nextcloud.com/t/occ-dashboard-command-not-working-as-documented/192844/8

[SystemKeeper]

/backport to stable29

[SystemKeeper]

/backport to stable28

[joshtrichards]

/backport to stable27

[backportbot]

The backport to stable27 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable27
git pull origin stable27

# Create the new backport branch
git checkout -b backport/11843/stable27

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick dd59014a

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/11843/stable27

Error: No changes found in backport branch

---

Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.

[joshtrichards]

Guess this feature missed getting into the 27 docs by a few days. Hah. Taking care of in #11849 then we can do the backport here again too of this fix.