chore(deps): bump chroma to v2 #735

Bump `alecthomas/chroma` to `v2`:
https://github.com/cheat/cheat/issues/735

vendor/github.com/alecthomas/chroma/v2/formatters/json.go

@@ -0,0 +1,31 @@
+package formatters
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/alecthomas/chroma/v2"
+)
+
+// JSON formatter outputs the raw token structures as JSON.
+var JSON = Register("json", chroma.FormatterFunc(func(w io.Writer, s *chroma.Style, it chroma.Iterator) error {
+	fmt.Fprintln(w, "[")
+	i := 0
+	for t := it(); t != chroma.EOF; t = it() {
+		if i > 0 {
+			fmt.Fprintln(w, ",")
+		}
+		i++
+		bytes, err := json.Marshal(t)
+		if err != nil {
+			return err
+		}
+		if _, err := fmt.Fprint(w, "  "+string(bytes)); err != nil {
+			return err
+		}
+	}
+	fmt.Fprintln(w)
+	fmt.Fprintln(w, "]")
+	return nil
+}))