Replace gridbuilder.info with gridbuilder.info.yml

Hi there!
Please replace the existing gridbuilder.info with the newer gridbuilder.info.yml:

name: Grid Builder
description: Simple grid system builder.
package: Core Extension
version: VERSION
core: 8.x
type: module
dependencies:
  - breakpoint
  - config
configure: admin/structure/gridbuilder

• We should consider keeping the language/wording consistent/congruent:
  This is why the configuration path ends with the full name in one word.