Feat/shortcuts

[Blankll]

add more shortcuts

refer: #36

Feature	Shortcut	Description	State
General editing	Ctrl/Cmd + I	Auto indent current request.	✅
General editing	Ctrl + Space	Open Autocomplete (even if not typing).	✅
General editing	Ctrl/Cmd + Enter	Submit request.	✅
General editing	Ctrl/Cmd + Up/Down	Jump to the previous/next request start or end.	✅
General editing	Ctrl/Cmd + Alt + L	Collapse/expand current scope.	✅
General editing	Ctrl/Cmd + Option + 0	Collapse all scopes but the current one. Expand by adding a shift.	✅
Autocomplete	Down arrow	Switch focus to autocomplete menu. Use arrows to further select a term.	✅
Autocomplete	Enter/Tab	Select the currently selected or the top most term in autocomplete menu.	✅
Autocomplete	Esc	Close autocomplete menu.	✅