Add troubleshooting section for Flutter build error with localizations

[0xharkirat]

Pull Request Description: Adding Common Issue for Localization Build Error

Description:

This pull request adds a new entry to the Common Issues section under Troubleshooting to help users resolve a frequent build error encountered when using localizations in Flutter. The error typically occurs when the necessary localization files are not generated during the build process, resulting in a Try correcting the name to the name of an existing getter, or defining a getter or field named 'AppLocalizations'. error.

Changes Made:

• Added a new entry to the Common Issues section under Troubleshooting.
• Added the solution to run the flutter gen-l10n command in the pre-build script.

Checklist:

• The description is concise and follows the format of existing entries.
• Log output and example scripts are included.
• Links to official Flutter documentation are provided.
• Reviewed and tested for accuracy.

Additional Notes:

Feedback and suggestions for improvement are welcome. If there are any adjustments needed, I'd be happy to make them.

[0xharkirat]

this is the screenhshot of changes made:

[0xharkirat]

any comments. still waiting for review thanks.