feat: preserve comments from golang -> typescript

[Emyrk]

Inspired by #53

This is an opt-in feature to be backwards compatible.

To use:

gen, _ := guts.NewGolangParser()

// PreserveComments will attach golang comments to the typescript nodes.
gen.PreserveComments()

Example:

// Foo is the structure to contain things
type Foo struct {
	Bar string // Bar is important
	// Bazz is less important but has more comments
	// associate with it.
	Bazz int
}

// From comments/comments.go
// Foo is the structure to contain things
export interface Foo {
    readonly Bar: string; // Bar is important
    // Bazz is less important but has more comments
    // associate with it.
    readonly Bazz: number;
}

Limitations

This PR only covers a subset of cases right now. More will have to be added

[Emyrk]

@stavros-k I think this might cover most of your use case? I think I'll merge and release this as is, and improve on it over time.

[stavros-k]

Looks good yea! Thanks

[Emyrk]

@stavros-k I made a new release of guts with this change 👍