feat: Add Time Marker Detection in Episode Descriptions

[mfcar]

Here's the corrected text for your pull request:

Several podcast apps, such as Overcast and Pocket Cast, have a feature that detects Time Markers in the episode description. This feature provides a way to jump directly to that time. It's very similar to chapters, but the time markers aren't embedded in the files; they are automatically detected from the description.

This PR adds support for detecting time markers in the AudioBookShelf app as well.

The detector identifies time markers in multiple formats (at least minutes and seconds):

H:M:SS
H:MM:SS
HH:MM:SS
H:M:SS

---

Demo

Screen.Recording.2024-05-19.at.14.16.51.mov

[advplyr]

This is great. The RSS feed for Syntax has an issue because they put a link around their timestamps.
https://feed.syntax.fm/rss

I couldn't think of a way to handle false positives better. The regex gets complicated when trying to handle these different cases so I'm not sure if it is worth it.

[nichwall]

Maybe just adding something like the following to ignore matches that have more than 2 digits on the end parts by checking that the preceding or following character is not a digit (like the link with a port in it). Not sure if that's worth it or how often ports would show up in a link.

Before: \b(?<!\d)
After: ?(?!\d)\b

[mfcar]

Thanks @advplyr and @nichwall for the feedback.

I was investigating the Syntax RSS feed, and they use an anchor link for the time marker, but the anchor only works on their page. I tested the same feed on other apps and got the following results:

1. PocketCasts: Uses a different color for the anchor links, but when you tap them, nothing happens.
2. Overcast: Uses the same color for the external links, and like PocketCasts, tapping them does nothing.
3. Apple Podcasts: Doesn't render anchor links, only regular links.

---

Based on this, I made some adjustments to the code to handle anchor links in the detector. If a time marker is inside an anchor link (which won't work because we're not on the website page), I replace it with a detectable time marker (the other links remain unchanged).

---

Based on advplyr's test cases, I tested with additional edge cases, and the detector worked well. As nichwall suggested, I changed the script to avoid URLs with a port value, but if the URL contains at least two colons, I can't detect this, or if it is an plain anchor url

Here are some tests that I generated to check:

[advplyr]

Great, thanks!