Resolve #3321487 "Readme.txt with readme.md"

Closes #3321487

bootstrap_default_classes/bootstrap_default_classes.info.yml

 name: Bootstrap Utilities - Default classes [deprecated]
 type: module
 description: Bootstrap utilities - Default classes for CKEditor adds filter settings to add all default classes from Bootstap. For example add .table by default to added tables. [deprecated - code moved to main module]
+lifecycle: deprecated
+lifecycle_link: https://www.drupal.org/project/bootstrap_utilities/issues/3306260
 core: 8.x
 package: Bootstrap Utilities
 dependencies: