Add i18n (Internationalization) Support

[kap1bala]

Hello!

I've noticed that WebInstaller currently lacks internationalization (i18n) support. As a user/developer interested in this project, I would like to contribute by adding i18n functionality to WebInstaller.

Motivation:
This will improve the experience for non-native English speakers, lowering the barrier to entry and helping the project attract a broader global audience of users and contributors.

Plan (Initial Idea):

• Architecture: Considering the project's need for lightness, I propose an initial implementation using native JavaScript. The plan is to add data-i18n attributes to HTML tags that require translation and use a simple JavaScript function to load and replace text content.
• Contribution: I can complete the setup of the entire framework and provide a complete Chinese (Simplified) translation.
• Backward Compatibility: The default language will remain English, and all changes will be non-breaking, ensuring no impact on existing functionality.

If this proposal is accepted in principle, I would be happy to create a Pull Request for demonstration and further discussion.

[lost-hope]

Please go ahead. There are some text parts in the installer code, that is imported. I guess that is a part that cant be translated right?

[kap1bala]

Please go ahead. There are some text parts in the installer code, that is imported. I guess that is a part that cant be translated right?

• Before starting the i18n work, some refactoring is required, once Refactor: improve robustness #68 is merged, I will start i18n work immediately.
• I noticed the i18n problem with esp-web-tools, too. There must be some obstacle, maybe the best solution is submit a PR to esp-web-tools repo directly, i will continue to research it :)