Error running demo

[joshcarp]

Looks like it might be a go mod issue:

sysl-catalog --serve demo.sysl   
Serving on http://localhost:6900
error parsing "github.com/anz-bank/sysl-examples/demos/sizzle_restaurant/sizzle.sysl": no go.mod file, run `go mod init` first

ERRO[0000] Error creating project markdown:template: 0:6:21: executing "0" at <MacroPackages .Module>: error calling MacroPackages: runtime error: invalid memory address or nil pointer dereference 
0 [_____________________________________________________________________________________________________________________________________________________________] ?% ? p/s 0s
The generated files are output to folder `/`