fix: improve LoadValues function documentation

Signed-off-by: lubingtan <bingtanlu@gmail.com>

pkg/chart/loader/load.go

@@ -207,7 +207,10 @@ func LoadFiles(files []*BufferedFile) (*chart.Chart, error) {
 	return c, nil
 }
 
-// LoadValues loads chat values from a reader.
+// LoadValues loads values from a reader.
+//
+// The reader is expected to contain one or more YAML documents, the values of which are merged.
+// And the values can be either a chart's default values or a user-supplied values.
 func LoadValues(data io.Reader) (map[string]interface{}, error) {
 	values := map[string]interface{}{}
 	reader := utilyaml.NewYAMLReader(bufio.NewReader(data))