Merging with paoloose/urn

[EXtremeExploit]

Original: https://github.com/LibreSplitDev/LibreSplit/issues/12

Basically LibreSplit and paoloose/urn (both urn forks) started at around the same time, without noticing each other,

@paoloose has agreed that his fork's work to be merged into LibreSplit as it would be much easier to do so, and just better to avoid fragmentation

• Icons support for splits
• Feedback error when opening invalid JSON files
• Remembering the last opened split folder
• Creating a new default theme, as similar as possible to the original LiveSplit look
• New shortcut to keep window always on top (Ctrl+K)
• Comprehensive documentation
• More themes

• [x] Icons support for splits https://github.com/LibreSplit/LibreSplit/pull/117
• [x] Feedback error when opening invalid JSON files https://github.com/LibreSplit/LibreSplit/pull/49
• [x] Remembering the last opened split folder https://github.com/LibreSplit/LibreSplit/pull/127
• [ ] Creating a new default theme, as similar as possible to the original LiveSplit look
• [x] New shortcut to keep window always on top (Ctrl+K) https://github.com/LibreSplit/LibreSplit/issues/99 https://github.com/LibreSplit/LibreSplit/pull/118
• [x] Comprehensive documentation https://github.com/LibreSplit/LibreSplit/pull/122
• [ ] More themes, either by porting already existing urn themes or changing how themes work to make them compatible

[wins1ey]

Feedback error when opening invalid JSON files

Already implemented #49

[Penaz91]

Managed to track down some themes for Urn (the owner seems to have moved to GitLab):

• https://gitlab.com/AsahiNyan/asahi-ann
• https://gitlab.com/AsahiNyan/Catppuccin-Urn-Gtk
• https://gitlab.com/AsahiNyan/real-ann