This package allows you to remember your current cursor position,
go somewhere else and then jump between those two positions.  It is
meant for quick detours and then continuing your work where you
left off.

Suggested keybindings:
(global-set-key [(control \.)] 'detour-mark)
(global-set-key [(control \,)] 'detour-back)

Or via use-package:

(use-package detour
  :bind
  ([(control \.)] . detour-mark)
  ([(control \,)] . detour-back))

Internally, a register is used to store the position.  If you
manually set this register, these functions will not work.