`:vsp [file]` should create file if it doesn't exist

First, thanks very much for creating this extension. The vim emulation is good enough that I've taken the plunge into vscode.

In regular vim and neovim, I rely a lot on :vsp to create a new file in the current working directory. That doesn't work in vscode-vim. Can it be made to work the way I've gotten accustomed to, namely:

:vscode <filename> creates a new vertical split to the right of the active pane and opens the file there, creating it if it doesn't exist. New files are created in the current working directory if an absolute or relative path is not specified.

EDIT: Should be vsp <filename> above, (doh!)

The entry point named by the issue is the :vsp command; start by locating its TypeScript command handling and the existing vertical-split file-opening path. Done means :vsp opens a new vertical split to the right and creates the file when it does not exist, supporting relative and absolute paths.