Issue #2273337 by ducktape: Fix docs for add field methods for Schema and db_add_field()

core/includes/database.inc

@@ -731,7 +731,7 @@ function db_drop_table($table) {
  *   will be set to the value of the key in all rows. This is most useful for
  *   creating NOT NULL columns with no default value in existing tables.
  * @param $keys_new
- *   Optional keys and indexes specification to be created on the table along
+ *   (optional) Keys and indexes specification to be created on the table along
  *   with adding the field. The format is the same as a table specification, but
  *   without the 'fields' element. If you are adding a type 'serial' field, you
  *   MUST specify at least one key or index including it in this array. See
@@ -911,7 +911,7 @@ function db_drop_index($table, $name) {
  * @param $spec
  *   The field specification for the new field.
  * @param $keys_new
- *   Optional keys and indexes specification to be created on the table along
+ *   (optional) Keys and indexes specification to be created on the table along
  *   with changing the field. The format is the same as a table specification
  *   but without the 'fields' element.
  */

core/lib/Drupal/Core/Database/Schema.php

@@ -437,7 +437,7 @@ public function fieldExists($table, $column) {
    *   This is most useful for creating NOT NULL columns with no default
    *   value in existing tables.
    * @param $keys_new
-   *   Optional keys and indexes specification to be created on the
+   *   (optional) Keys and indexes specification to be created on the
    *   table along with adding the field. The format is the same as a
    *   table specification but without the 'fields' element. If you are
    *   adding a type 'serial' field, you MUST specify at least one key
@@ -651,7 +651,7 @@ public function fieldExists($table, $column) {
    * @param $spec
    *   The field specification for the new field.
    * @param $keys_new
-   *   Optional keys and indexes specification to be created on the
+   *   (optional) Keys and indexes specification to be created on the
    *   table along with changing the field. The format is the same as a
    *   table specification but without the 'fields' element.
    *