Here it is.
Ctrl+Shift+[ Fold (collapse) region editor.fold
Ctrl+Shift+] Unfold (uncollapse) region editor.unfold
Ctrl+K Ctrl+[ Fold (collapse) all subregions editor.foldRecursively
Ctrl+K Ctrl+] Unfold (uncollapse) all subregions editor.unfoldRecursively
Ctrl+K Ctrl+0 Fold (collapse) all regions editor.foldAll
Ctrl+K Ctrl+J Unfold (uncollapse) all regions
Take Look at Visual studio Code Keybindings section at this link.
Also Platform specific Key board shortcuts available in pdf.here is the links
Windows,MAC,Linux