Update ingredients tooltip to remove obsolete instructions

[github-throwaway]

What

As confirmed by @stephanegigandet on slack it is not required anymore to surround allergens with underscores. Thus, the text should be updated.

Steps to reproduce the behavior

Just open any ingredients edit page.

Expected behavior

What this text field should contain and what it shouldn't. An explanation of what happens automatically and what needs to be done manually. It should clearly state what OFF considers as ingredients and what not. Are allergens or trace part of this text field? What about comments regarding organic origin? The text should make this clear.

Why

So that the user knows what's happening and does not have to guess.

Part of

• 🎯 What can I work on ? #525

Screenshot/Mockup/Before-After

Smartphone model

• Device: iPhone 15 Pro Max
• OS: iOS
• App Version:

LocaleString: de_DE
Language: OpenFoodFactsLanguage.GERMAN
Country: OpenFoodFactsCountry.GERMANY
IsLoggedIn: true
UUID: 16a2e86b2af94eda
Matomo Visitor ID: C000000000000000
QueryType: QueryType.PROD
Domain: openfoodfacts.org
UserAgent-name: Smoothie - OpenFoodFacts
UserAgent-system: ios+Version 17.7 (Build 21H16)
User group: 0
SystemVersion: 17.7
Model: iPhone
localizedModel: iPhone
Version: 4.16.1
BuildNumber: 1364
Scanner: Instance of 'ScannerMLKit'
Store: StoreLabel.AppleAppStore
PackageName: org.openfoodfacts.scanner