open terminal buffer in terminal mode

No need to press an extra key to go into terminal mode once inside the
`gh
dash` floating window (`gh dash` keybinds will work immediately after
popup
opens).

Author: appositum

lua/gh_dash/init.lua

@@ -102,6 +102,8 @@ local function open_window()
     style = 'minimal',
     border = border,
   })
+
+  vim.cmd('startinsert')
 end
 
 function M.open()