* updated build.zig and generate_functions.py to add raygui
* added raygui.h and manually coded some structs & enums in raygui prelude WIP
* ported all the structs, enums and globals to zig till raygui implementation
* imported types from raylib in raygui
* re-encoded raygui-prelude.zig. I don't know for some reason it was showing up as UTF-16 unicode text file. re-encoded it to UTF-8
* fixed imports in prelude to work properly with generated files
* updated generate_functions.py file to generate for raygui [text type error not fixed]
* simple temporary patch for mentioned text type issue
* removed unused imports from raylib in raygui
* added generated files
* Manually define raygui functions for slice arguments
* Manually define raygui functions with pointer return values
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Co-authored-by: Not-Nik <nik.wipper@gmx.de>
