Proposal: shell completion for --framework flag

[MitchellBerend]

It would be nice if the completion command would also generate completion for the --framework flag. It will help with feature discovery for new users.

[basokant]

Every Cobra CLI app has access to the

go-blueprint completion [bash/zsh/fish]

command, which generates shell completions.

HOWEVER, a bit of setup is required for permitted flag values in Cobra, which would be required to get autocomplete working for the --framework flag. See https://stackoverflow.com/questions/50824554/permitted-flag-values-for-cobra/70541824#70541824

1. Make a new type that implements the pflag.Value interface, that is also a string enum (ie. frameworkEnum), which enumerates the possible frameworks that we support.
2. Use enum in the registration of the create command. See init() function.

cmd.Flags().Var(&frameworkEnum, "framework", `framework. allowed: "chi", "standard library", "gin", etc...`)

[basokant]

I might take this guy, will start working on it later tho so if anyone wants to work on it go ahead (check out the comment above for some tips from yours truly 😄)