deps: Update go-org to v1.4.0

- Add support for pretty urls [1]. Rewrite file links:
  1. replace the `.org` extension with `/` (`/foo.org` -> `/foo/`)
  2. prefix unrooted links with `../` as relative links start in the fake
  subdirectory `/foo/` rather than `/`
- Fix case-sensitivity of org drawer `🔚`

[1] https://gohugo.io/content-management/urls/#pretty-urls

markup/org/convert_test.go

@@ -17,6 +17,7 @@ import (
 	"testing"
 
 	"github.com/gohugoio/hugo/common/loggers"
+	"github.com/spf13/viper"
 
 	"github.com/gohugoio/hugo/markup/converter"
 
@@ -25,7 +26,10 @@ import (
 
 func TestConvert(t *testing.T) {
 	c := qt.New(t)
-	p, err := Provider.New(converter.ProviderConfig{Logger: loggers.NewErrorLogger()})
+	p, err := Provider.New(converter.ProviderConfig{
+		Logger: loggers.NewErrorLogger(),
+		Cfg:    viper.New(),
+	})
 	c.Assert(err, qt.IsNil)
 	conv, err := p.New(converter.DocumentContext{})
 	c.Assert(err, qt.IsNil)