[DOCS] Fix bind-attr example code
[BUGFIX beta] Use new transform syntax.

* Update to HTMLBars 0.5.0
* Make AST transforms not require Walker to be imported.
* Add some additional YUIDocs to Transform Factories.
Merge pull request #9848 from knownasilya/patch-2

[DOCS] Fix bind-attr example code
[BUGFIX beta] Allow tagName to be a CP with deprecation
Merge pull request #9905 from mixonic/allow-tagName-cp-with-dep

[BUGFIX beta] Allow tagName to be a CP with deprecation
Merge pull request #9903 from rwjblue/update-htmlbars

[BUGFIX beta] Use new transform syntax.