Use a dynamic hint for the smerge transient state in order to show the
current and total numbers of conflicts, and make the full hint toggleable.
* CHANGELOG.develop: Add an entry for this change.
* layers/+source-control/version-control/config.el
(spacemacs--smerge-ts-full-hint-toggle): New variable.
* layers/+source-control/version-control/funcs.el
(spacemacs//smerge-ts-hint): New function. Return a string indicating the
index of the current conflict and the total number of conflicts detected by
smerge-mode. If spacemacs--smerge-ts-full-hint-toggle is true, append the
smerge transient state's full hint.
(spacemacs//smerge-ts-toggle-hint): Toggle showing the full hint for the
smerge transient state.
* layers/+source-control/version-control/packages.el
(version-control/init-smerge-mode): Define the transient state in :init so
we can use spacemacs|transient-state-format-hint. Use
spacemacs//smerge-ts-hint to display a dynamic hint. Bind the ? key to
spacemacs//smerge-ts-toggle-hint.
