Add vendor files for go build

vendor/github.com/alecthomas/chroma/formatters/api.go

@@ -0,0 +1,55 @@
+package formatters
+
+import (
+	"io"
+	"sort"
+
+	"github.com/alecthomas/chroma"
+	"github.com/alecthomas/chroma/formatters/html"
+)
+
+var (
+	// NoOp formatter.
+	NoOp = Register("noop", chroma.FormatterFunc(func(w io.Writer, s *chroma.Style, iterator chroma.Iterator) error {
+		for t := iterator(); t != chroma.EOF; t = iterator() {
+			if _, err := io.WriteString(w, t.Value); err != nil {
+				return err
+			}
+		}
+		return nil
+	}))
+	// Default HTML formatter outputs self-contained HTML.
+	htmlFull = Register("html", html.New(html.Standalone(), html.WithClasses())) // nolint
+)
+
+// Fallback formatter.
+var Fallback = NoOp
+
+// Registry of Formatters.
+var Registry = map[string]chroma.Formatter{}
+
+// Names of registered formatters.
+func Names() []string {
+	out := []string{}
+	for name := range Registry {
+		out = append(out, name)
+	}
+	sort.Strings(out)
+	return out
+}
+
+// Get formatter by name.
+//
+// If the given formatter is not found, the Fallback formatter will be returned.
+func Get(name string) chroma.Formatter {
+	if f, ok := Registry[name]; ok {
+		return f
+	}
+	return Fallback
+}
+
+// Register a named formatter.
+func Register(name string, formatter chroma.Formatter) chroma.Formatter {
+	Registry[name] = formatter
+	return formatter
+}