I know how to modify and create code snippets and I know how to modify shortcut keys, but how does one bring those 2 together?
It would seem that, as of version 1.9, Visual Studio Code can do what you are looking for, no other extensions necessary.
From https://code.visualstudio.com/updates/v1_9#_insert-snippets
"You can now bind your favorite snippets to key bindings. A sample that encloses a selection with single quotes looks like this:"
Add the snippet below to keybindings.json (open Keyboard Shortcuts editor and click on the For advanced customizations open and edit keybindings.json link)
{
"key": "cmd+k",
"command": "editor.action.insertSnippet",
"args": { "snippet": "'$TM_SELECTED_TEXT'" }
}