Ruby Sublime config itemsItems from user_settings should be added in "Preferences" > "Settings - User"Items from user_key_bindings should be added in "Preferences" > "Key bindings - User"

user_key_bindings.py

{ "keys": ["ctrl+t"], "command": "expand_tabs", "args": { "set_translate_tabs": true } }

user_settings.py

// The number of spaces a tab is considered equal to
"tab_size": 2,

// Set to true to insert spaces when tab is pressed
"translate_tabs_to_spaces": true,

// If translate_tabs_to_spaces is true, use_tab_stops will make tab and
// backspace insert/delete up to the next tabstop
"use_tab_stops": true,

// Set to "none" to turn off drawing white space, "selection" to draw only the
// white space within the selection, and "all" to draw all white space
"draw_white_space": "all",

"trim_trailing_white_space_on_save": true,