Google’s documentation says:
> robots.txt is not a mechanism for keeping a web page out of Google. To
> keep a web page out of Google, you should use noindex directives
A noindex directive means adding the following meta tag to pages that
shouldn’t be indexed:
```html
<meta name="robots" content="noindex" />
```
It’s also possible to set the directive as a HTTP header, but this seems
trickier to achieve on a per-view basis in Flask.
I’ve implemented this as a decorator so it can quickly be added to any
other pages that we decide shouldn’t appear in search results.
92ffe3a78c