More textboxes

@Petsnew We need to pick a chapter on which we will beta-test this feature. Which chapter is your DLL for? Also is it merged with our latest DLL? Can you create a branch in the dlls repo with your changes?

As for configuration, @idealpersona implemented it in https://github.com/07th-mod/higurashi-dlls/issues/19 though I'm unsure if it is everywhere and ready to base new features on it. Let's wait for his feedback.

Next, do you intend to support https://github.com/07th-mod/higurashi-patch-compiler/issues/35 as well or not?

Which key is the user supposed to press to change a textbox?

FInally we'll need some textboxes to test this feature. Do you have something simple? Or should we ask @Grelo to create something?

The issue discusses adding a textbox feature, referencing a DLL chapter, configuration from issue #19, and support for issue #35. Start by examining the linked issues and the dlls repository to understand the current architecture. Determine which key triggers the textbox change and what simple test textboxes are needed. The work involves coordination with multiple contributors and unclear scope.

Written by the indexing model from the issue text.