docs: bad octal number representation about yii2-apidoc

[hiqsol]

@hiqsol want to send a PR to apidoc extension?

Yes.
But I know nothing about yii2-apidoc architecture.
Please tell me where should it go? Are there unit tests?

[cebe]

The default value for methods is here:

• yii2-apidoc/templates/html/ApiRenderer.php

  Line 265 in ddb9625

  . ($param->isOptional ? ' = ' . $param->defaultValue : ''),

This for properties:

• yii2-apidoc/templates/html/ApiRenderer.php

  Line 250 in ddb9625

  . ApiMarkdown::highlight('= ' . ($property->defaultValue === null ? 'null' : $property->defaultValue), 'php');

There should be the check on how to display the value.

[cebe]

there are no tests, for testing you need to generate the docs by running the apidoc command and check the result.