Here's a current list inside the file editor, taken straight from the source code:
extraKeys =
"Alt-Enter" : (editor) => @action_key(execute: true, advance:false, split:false)
"Cmd-Enter" : (editor) => @action_key(execute: true, advance:false, split:false)
"Ctrl-Enter" : (editor) => @action_key(execute: true, advance:true, split:true)
"Ctrl-;" : (editor) => @action_key(split:true, execute:false, advance:false)
"Cmd-;" : (editor) => @action_key(split:true, execute:false, advance:false)
"Ctrl-\\" : (editor) => @action_key(execute:false, toggle_input:true)
#"Cmd-x" : (editor) => @action_key(execute:false, toggle_input:true)
"Shift-Ctrl-\\" : (editor) => @action_key(execute:false, toggle_output:true)
#"Shift-Cmd-y" : (editor) => @action_key(execute:false, toggle_output:true)
"Ctrl-S" : (editor) => @click_save_button()
"Cmd-S" : (editor) => @click_save_button()
"Ctrl-L" : (editor) => @goto_line(editor)
"Cmd-L" : (editor) => @goto_line(editor)
"Ctrl-I" : (editor) => @toggle_split_view(editor)
"Cmd-I" : (editor) => @toggle_split_view(editor)
"Shift-Ctrl-." : (editor) => @change_font_size(editor, +1)
"Shift-Ctrl-," : (editor) => @change_font_size(editor, -1)
"Shift-Cmd-." : (editor) => @change_font_size(editor, +1)
"Shift-Cmd-," : (editor) => @change_font_size(editor, -1)
"Shift-Tab" : (editor) => editor.unindent_selection()
"Ctrl-Space" : "indentAuto"
"Ctrl-'" : "indentAuto"
"Tab" : (editor) => @press_tab_key(editor)
"Shift-Ctrl-C" : (editor) => @interrupt_key()