[feature request] more shortcuts

hope more shortcuts:
insert new line above/below ( editor.action.insertLineAfter and editor.action.insertLineBefore in vscode)
Copy Line Down (editor.action.copyLinesDownAction in vscode )
scroll Line Down/Up ( scrollLineDown in vscode)
Expand Line Selection (expandLineSelection in vscode)

thanks!

Use the VS Code command names in the issue as the behavior reference, then locate the editor's existing shortcut or command definitions. Add support for inserting lines above and below, copying a line down, scrolling one line up or down, and expanding line selection. Verify each shortcut manually using the editor's normal interaction flow.

Written by the indexing model from the issue text.