add switch case template function

[j-lakeman]

Would be quite helpful IMHO if one could do sth like

{{ switch .chezmoi.os }}
{{ case "linux" }}
{{ case default }}
{{ end }}

Could save lots of if eq .chezmoi.os … else if eq .chezmoi.os ….

[bradenhilton]

I don't think it's possible to do this with text/template

[halostatue]

@bradenhilton is correct. This is a syntax thing that would need extension in text/template, and the Go language developers/designers have deliberately not added Go's switch to text/template.