fix(state): enhance error message for missing .gotmpl extension in helmfile

Signed-off-by: yxxhero <aiopsclub@163.com>

pkg/state/create.go

@@ -109,7 +109,7 @@ func (c *StateCreator) Parse(content []byte, baseDir, file string) (*HelmState,
 		if err == io.EOF {
 			break
 		} else if err != nil {
-			return nil, &StateLoadError{fmt.Sprintf("failed to read %s: reading document at index %d", file, i), err}
+			return nil, &StateLoadError{fmt.Sprintf("failed to read %s: reading document at index %d, you shuld add .gotmpl extension to your helmfile to enable helmfile to load it as a template since helmfile v1", file, i), err}
 		}
 
 		if err := mergo.Merge(&state, &intermediate, mergo.WithAppendSlice); err != nil {