Keyboard shortcuts can be configured (and reviewed) via the Settings dialog, accessible via File -> Settings
.
Once this dialog appears, to review (and/or add) a shortcut, do the following:
Select Keymap in the list on the left. Note that there is a "Keymaps" option, and depending on the original selection, shortcuts assigned to a given feature differ based on the Keymap.
Type "comment" or text corresponding to the feature for which the keyboard shortcut is to be reviewed/assigned. Each match has a line entry in the list below, and keyboard shortcuts are shown right-justified along with the feature. For example, both CTRL+ALT+SLASH and CTRL+K, CTRL+C are the two assignments for creating a line comment.
To modify a shortcut: