code: function validateBemDecl(bemDecl, fileName) {
    let errors = [];
  
    bemDecl.forEach((decl) => {
      errors = errors.concat(validateBemDeclItem(decl, fileName));
    });
  
    return errors;
  }
docs: Validate BEM declarations
  
  @param {Array} bemDecl
  @param {String} fileName
  @return {Array} of validation errors