Custom chapter size

[po5]

Lets the user customize the width of chapter markers.
Also handles the case of not overlapping chapters that are very close together (in timeline_chapters=lines style, dots can still overlap).

[tomasklaen]

Set the default timeline_chapters_width to 6. Then split the current chapter_size variable into chapter_width and chapter_height, and determine their values in the if/else switch above the rendering. For example for dots:

- chapter_size = math.min(6, (foreground_size / 2) + 1)
+ chapter_width = math.min(options.timeline_chapters_width, (foreground_size / 2) + 1)

Then use them in rendering.

And remove the overlapping prevention. It's valuable to have a visual cue that there are multiple chapters on top of each other, otherwise it'll look like a chapter range bar.

[tomasklaen]

Sorry I've touched the whole code block with chapters in last commit, you'll have to rebase 😯.

[tomasklaen]

Had a bit of time and wanted to include this in the next release, so I went ahead.