This commit adds support for line based comments on struct fields and
Encore will now pick those up if there is not a doc comment on the field
```go
type FooBar struct {
// This is a doc comment on Field
Field string
// This doc comment will take presendence over the line comment
Foo string // This is a line comment will be ignored
Bar string // This is a line comment will be used as the documentation
}
```
This example will result in the following documentation generation:
> `Field`: This is a doc comment on Field
> `Foo`: This doc comment will take presendence over the line comment
> `Bar`: This is a line comment will be used as the documentation