Issue #2852182 by xjm: Fix list indentation in recently committed committed Migrate documentation

core/modules/migrate/src/Plugin/migrate/process/Callback.php

@@ -14,7 +14,7 @@
  * argument. No additional arguments can be passed to the callback.
  *
  * Available configuration keys:
- *   - callable: The name of the callable method.
+ * - callable: The name of the callable method.
  *
  * Examples:
  *

core/modules/migrate/src/Plugin/migrate/process/Concat.php

@@ -14,8 +14,8 @@
  * set of strings into a single string.
  *
  * Available configuration keys:
- *   - delimiter: (optional) A delimiter, or glue string, to insert between the
- *     strings.
+ * - delimiter: (optional) A delimiter, or glue string, to insert between the
+ *   strings.
  *
  * Examples:
  *

core/modules/migrate/src/Plugin/migrate/process/SkipRowIfNotSet.php

@@ -15,7 +15,7 @@
  * is thrown.
  *
  * Available configuration keys:
- *   - index: The source property to check for.
+ * - index: The source property to check for.
  *
  * Example:
  *