Adds ``Filter Keywords``, a preset that can include or exclude media with any of the listed keywords. Both keywords and title/description are lower-cased before filtering.
Supports the following override variables:
* ``title_include_keywords``
* ``title_exclude_keywords``
* ``description_include_keywords``
* ``description_exclude_keywords``
For best usage, use the `~` tilda subscription mode to set a subscription's list override variables.
Tilda mode allows override variables to be set directly underneath it.
```
Plex TV Show by Date | Filter Keywords:
= Documentaries:
"~NOVA PBS":
url: "https://www.youtube.com/@novapbs"
title_exclude_keywords:
- "preview"
- "trailer"
"~To Catch a Smuggler":
url: "https://www.youtube.com/@NatGeo"
title_include_keywords:
- "To Catch a Smuggler"
```
