Fix uninstall rule

    $(MAN)/$(PROGRAM).1  ->  $(MAN)/man1/$(PROGRAM).1
Don't use xdotool

It's too complicated for these simple example scripts.
Improve xdotool usage

-   ‘command -v’ commands are silenced
-   dicemenu’s command menu is now also shown in the active window if
Stop shellcheck from complaining
Try to position dicemenu in the active window
Fix uninstallation of doc files
Fix doc location for Makefile
Protect directory argument

Fixes an issue where e.g. `pathmenu -- -P' would lead to `cd -P' being
executed causing pathmenu to start in the home directory; or `pathmenu
-- -x' would lead to the invalid option `cd -x' causing cd(1) to fail.
Reword man page to be more consistent
Update man page and usage text
Update dicemenu command suggestions
dicemenu: Return to pathmenu if dice’s dmenu fails

The eval will not take place if the dmenu command in
‘cmd=$(... | dmenu ...)’ fails.

Prior to this patch, dicemenu as a whole would exit immediately
if ESC was pressed in the dice stage.
Fix dicemenu prompt string
dicemenu: Don’t suggest less/vi for non-files
dicemenu: remain in the last working directory
dicemenu: Show number of hiddens args in prompt