v1.34 Minor updates

Implemented Increase Line Spacing Before and After and other suggestions in #44.

Update README.md

Update 1.21

Updated settings dialog, taking locale settings into account. Added cleanup function: Remove hidden slides

New version 1.2

Instrumenta now has a settings dialog!
- change display mode of the Instrumenta Ribbon (pro-mode and review mode)
- set default step size for margin increase and decrease
- set default step size for row gaps and column gaps
- change default text of sticky notes

Merge branch 'main' of https://github.com/iappyx/Instrumenta

Further improving handling shapes within groups

Most functions now support shapes within groups (subselection within a group). E.g. Align only selected shapes in a group

🎉 First major release of Instrumenta!