Add translation markers to codelab elements. (googlecodelabs#538)

* Add translation markers to google_codelab.soy.

* Add translation markers to google_codelab_index.soy.

* Add translation markers to google_codelab_step.soy.

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update BUILD.bazel

* Update google_codelab.soy

* Update google_codelab_index.soy

Merge pull request googlecodelabs#472 from cassierecher/master

Run module tidy.

Merge pull request googlecodelabs#472 from cassierecher/master

Run module tidy.

Merge pull request googlecodelabs#445 from googlecodelabs/regen-tmpldata

Regenerated the template data file.

Merge pull request googlecodelabs#438 from MoonWolf125/markdown-butto…

…n-doc

Update Markdown Parser README Button Example

fix single newline in markdown input

Merge pull request googlecodelabs#238 from shawnbuso/fb2

Add id to feedback element.

Merge pull request googlecodelabs#234 from googlecodelabs/remove-about

Removed about section for now.

Remove potential line breaks from getting into codelab IDs and titles.

Merge pull request googlecodelabs#229 from googlecodelabs/template-ch…

…anges

Template changes