(referenced from syl20bnr/spacemacs#4856)
SPC t f to show the right margin line. By default this is set at 80 characters.
To activate for modes (for example):
;; Activate column indicator in prog-mode and text-mode
(add-hook 'prog-mode-hook 'turn-on-fci-mode)
(add-hook 'text-mode-hook 'turn-on-fci-mode)
M-q to automatically fill paragraphs to the value of fill-column.
Customise with (for example):
(setq-default fill-column 100)
Customise colour like:
(setq fci-rule-color "#FF0000")