Component Discovery: set the category

### Describe the problem

Component Discovery does not allow setting the category programmatically.

Use case: I'd like to preserve the hierarchical structure of my project in Weblate. See context below.

### Describe the solution you would like

There should be a Category option in the addon's setup, with a pattern. In my case (see context below), I'd be able to use this regex:

`translated/(?P[^/]+)/`**`(?Pplayers/(?:.+/)*)`**`(?P[^/]+)\.md`
`translated/language/`**`players/path/to/`**`file.md`

...and set the category to `{{ category }}`. This would result in the final URL being `/players/path/to/file`, and the project's home page would show the same hierarchical structure of the repo.

Note: it should also create categories that do not exist.

### Describe alternatives you have considered

1. Manually setting the categories post-discovery, but this defeats the purpose of the addon
2. Keep the auto-generated globs, which will not be grouped by folder and will clutter the home page.
- they might also create non-trivially predictable conflicts, for example `installing/java.md` and `installing-java.md` in the same directory.

### Screenshots

Not applicable

### Additional context

See full Discussion here:

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> We're evaluating Weblate as a potential alternative to Crowdin for the open-source [Fabric Documentation project](https://github.com/FabricMC/fabric-docs). Our translation file structure is:
>
> - Source: `a/**.md`, `b/**.md`
> - Translated: `translated/*/a/**.md`, `translated/*/b/**.md`
>
> I'd like Weblate's translation URLs to **preserve the original file path**; for example `a/path-to/file.md` should have its translation at `/a/path-to/file`.
> However, Weblate does not allow `/` in the `slug`, but categories do allow a hierarchical structure.
>
> The question is: **can Component Discovery automatically create and set the correct category?**
>
>
> Current Component Discovery setup
>
> - Regex: `translated/(?P[^/]+)/(?Pplayers/(?:.+/)*)(?P[^/]+)\.md`
> - Base: `{{ category }}{{ component }}.md`
>
>