Template, support optional argument

[sukrosono]

• kill @param Optional argument detection fails #552
• optional argument will be rendered between square bracket
• add literal (optional) on optional argument

[sukrosono]

Of the topic,

1. is that the optional argument will always be placed after the mandatory one?
2. it changes the clean template, does it change the default template?
   Also it untested, please guide me to properly testing it (if it necessary)

@jaapio , i think we agreed that we are going to changes the default template, right?

[jaapio]

Thanks for this PR,

In php terms an optional argument MUST be placed after all mandatory ones. You cannot simply omit a mandatory argument after an optional. function fooBar($optional = 'default', $required) {} cannot be called without errors.

The clean template is the default one.
At this moment we don't have any tests for templates since they are quite hard to write. There are a few of them but they are not working properly.

Could you please rebase this PR so only your changes are included?

[sukrosono]

Sure, captain @jaapio .
It would be a shame if the template doesn't change as we expect.
what i intent is manually test these changes since I don't have many experiences on composer.
I want to test it against my project. before it merged.
But i have no idea how to do it, i never release a project,
but really excited to know how the process involved.

Snap the rebase not clean as we expected, is this still a prob?
maybe i need your aid to rebase 😰