docs(step_15): create new step about accessibility

[felixzapata]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
Docs update to add a new step about accessibility

What is the current behavior? (You can also link to an open issue here)
The current tutorial is not accessible. With this new step you can learn how to fix the issues.

What is the new behavior (if this is a feature change)?
Introduce the accessibility into the tutorial.

Does this PR introduce a breaking change?
No, it does'nt. Only affects to the tutorial.

Please check if the PR fulfills these requirements

• The commit message follows our guidelines: https://github.com/angular/angular.js/blob/master/CONTRIBUTING.md#commit-message-format
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

Other information:
My opinion is this step should be a process inside of the tutorial. Not a separate step. This way the user can understand that is optional but it should be mandatory.

[gkalpak]

fyi @marcysutton

[gkalpak]

Could you add a paragraph on what is "accessibility" and "aria" and how it affects people. Just a brief summary and then list the links for more info.

[felixzapata]

ok, I'm on it.

[felixzapata]

I've added some definitions.

[gkalpak]

I left a few comments. Overall looks good 👍

A couple more necessary changes:

• Limit lines to 100 chars max.
• Don't mention anything protractor-related until the "Testing" section (except for the step summary at the top).
• I would rather not introduce new features at this point. Custom directives, $scope.$watch etc, are not explained before. Are they necessary?

[felixzapata]

For this example, I think is better the directives rather to use a component. These directives are needed to intercept the repeater and return the values to the aria regions. Maybe this can do it in another way.

Another option would be to remove the section "How to use the directives" and add a link to the Directives webpage.

[felixzapata]

@gkalpak I've made some updates. I will ping you, when I complete all of them (limit of lines, explanation of protractor accessibility plugin).

[marcysutton]

Here's one more article that was written in response to Angular a11y: https://www.smashingmagazine.com/2015/05/client-rendered-accessibility/

[felixzapata]

@gkalpak the limit of 100 characters is only for the code examples or all the document?

[gkalpak]

@felixzapata, the limit is for the whole document (where ever possible, e.g. if a URL is too long it's OK).
Is this ready for another review?

[felixzapata]

@gkalpak I have to review about the lines and I have to think what to do with the directives. Have you seen my previous comment about that? I mean, remove the section "How to use the directives" and add a link to the Directives webpage, instead of copy the code of the directives.

[felixzapata]

@gkalpak it is ready for another review:

• I've removed the information about directives. Now the tutorial has a link to the directives guide.
• I've removed the information about how to instal the ngAria module becuase, finally, is not used in this step.

When the step is approved, I will squash the commits.

[felixzapata]

@gkalpak it is ready for another review.

[felixzapata]

@gkalpak hi, any news about this pull request?

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please let us know the company's name.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please let us know the company's name.

[felixzapata]

I signed it!

[googlebot]

CLAs look good, thanks!

[googlebot]

CLAs look good, thanks!

[gkalpak]

Sorry it is taking so long, @felixzapata. It is still on my todo list. I'll get to it after 1.5.9 and 1.6.0-rc.0 are released.

[felixzapata]

ok @gkalpak