FR: Custom timestamp format for highlights

[greetclammy]

Describe the solution you'd like

Currently, the timestamp format for {{highlights}} cannot be configured, meaning you have to make do with long and unsightly timestamps like 2024-12-19T18:49:57.825Z.

It'd be wonderful if this was customizable somehow, just like how the date filter allows with other variables.

This would allow:

1. For tidier, prettier and more readable timestamps.
2. To set the timestamp format to be consistent with elsewhere in Obsidian & the clipper.