Version 0.12.2

This is a patch release with a small number of bug fixes and compatibility for bokeh 2.4. Many thanks to the contributors @Stubatiger, @maximlt, @nghenzi and the maintainers @MarcSkovMadsen and @philippjfr for the fixes in this release.

Enhancements:

• Add option to hide constant parameters on Param pane (#2637)
• Added on_session_destroyed callback (#2659)
• Stricter validation for linking syntax in ReactiveHTML._template (#2689)

Bug fixes:

• Improved thread safety (#2631)
• Ensure sessions get distinct files in config (#2646)
• Fix bug when updating Trend data (#2647)
• Ensure sorters are applied correctly after updating Tabulator value (#2639)
• Correctly reflect filtered data on Tabulator.selection (#2676
• Unescape child literal HTML in ReactiveHTML (#2690)
• Ensure Trend indicator can be rendered in layout (#2694)

Documentation:

• Enhance templates docs (#2658)
• Add Folium reference notebook (#2672)

Compatibility:

• Add support for bokeh 2.4 (#2644, #2687, #2696)