refactor(SubstitutionRow): Add comment

Author: binh-dam-ibigroup

lib/manager/components/transform/SubstitutionRow.js

@@ -155,6 +155,7 @@ export default class SubstitutionRow extends Component<Props, Substitution> {
           <FormGroup style={{ margin: 0 }} validationState={isEditingInvalid ? 'error' : null}>
             <InputGroup>
               <FormControl
+                // Autofocus the pattern field when user begins editing the substitution row.
                 // eslint-disable-next-line jsx-a11y/no-autofocus
                 autoFocus
                 onChange={this._onChangePattern}