Changed `core.redraw` to be set to `true` by default

As the window isn't created until the first frame is drawn this is required to
assure the window is ever shown without relying on the assumption that some
other part of the program would have set this to true

data/core/init.lua

···
   core.docs = {}
   core.threads = setmetatable({}, { __mode = "k" })
   core.project_files = {}
+  core.redraw = true
 
   core.root_view = RootView()
   core.command_view = CommandView()