Is there a keyboard shortcut to highlight text in Evince? To place a note? Or a way to setup a custom keyboard shortcut?
The feature was added just one month ago (August 10, 2018) to evince1.
I guess it will be available in the next evince version 3.31.
The shortcuts in the addition are S to add text annotation
and Ctrl+H to add highlight annotations.
1 See Merge Request “Allow Keybinding for highlighting annotation”.
So to get the keybindings in Ubuntu 18, I installed the latest version of evince from snap, as suggested by this answer (currently it is 40.4 as opposed to apt's 3.28.4).