Depth matching in paths

Hey! We are using Goggles for a search project with great success. However, one thing that would be extremely helpful is having some way to specify that we only want paths of a certain depth.

For example, if I am searching IMDB for movies but don't want to include any of the other pages they put beneath movies, I need to do:

```
"|https://www.imdb.com/title/$site=www.imdb.com",
"/title/*/parentalguide/$discard,site=www.imdb.com",
"/title/*/ratings/$discard,site=www.imdb.com",
"/title/*/crazycredits/$discard,site=www.imdb.com",
"/title/*/characters/$discard,site=www.imdb.com",
"/title/*/ratings/$discard,site=www.imdb.com",
"/title/*/taglines/$discard,site=www.imdb.com",
"/title/*/trivia/$discard,site=www.imdb.com",
"/title/*/awards/$discard,site=www.imdb.com",
"/title/*/fullcredits/$discard,site=www.imdb.com",
"/title/*/reviews/$discard,site=www.imdb.com",
"/title/*/goofs/$discard,site=www.imdb.com",
"/title/*/movieconnections/$discard,site=www.imdb.com",
"/title/*/plotsummary/$discard,site=www.imdb.com",
"/title/*/companycredits/$discard,site=www.imdb.com",
"/title/*/mediaviewer/$discard,site=www.imdb.com",
"/title/*/criticreviews/$discard,site=www.imdb.com",
"/title/*/alternateversions/$discard,site=www.imdb.com",
"/title/*/releaseinfo/$discard,site=www.imdb.com",
"/title/*/quotes/$discard,site=www.imdb.com",
```

This works, but its a lot of rules and its brittle in case IMDB add extra pages.

What I am really trying to say is that I want `/title/`, but not anything deeper than that.

Is there/could there be a way?

No implementation files or tests are identified in the issue. Start by tracing how Goggles path rules are parsed and matched; done means a rule can select /title/ while excluding deeper paths without enumerating child pages, with coverage for the requested behavior.

Written by the indexing model from the issue text.