Feature request: Let the user specify the Info-text as an option

[paleite]

The text on this particular line is hardcoded:

vue-form-generator/src/fields/core/fieldChecklist.vue

Line 11 in 56c075f

.info {{ selectedCount }} selected

Would be great if the user could specify the text instead.

[zoul0813]

@kmrov are those commits production ready? would you mind providing a PR?