Hello @xoofx
Following the PR I made for #599, I'm sharing the code I made.
This is an extra include_join function that is useful for small template. It made sound niche but it s extremelly useful. If you don't want it, i'll just modify the code that move the content of the original include function to TemplateContext for easier implementation.

I have found the following problems during my developments:

• A new unit test on newline_to_br is not working (it might be only when executing the test on windows) because the test is taken from builtins.md file and there is a miss with the \r character desptite the file being in LF mode.
• I figured out that the AsyncCodeGen project is dependant on Scriban project but the generated code is in Scriban project. It's the snake that bites its own tail. I wrote the generated code myself instead. How do you actually manage ScribanAsync.generated.cs file ?

#607

Thanks.