add wrap config option, default to false

Default to not wrapping long function names etc that are too big for the window.

If wrap=true is set, use some sane linebreak/breakindent/showbreak
options to wrap with an indent at the current indent level of the UI
tree, instead of just wrapping back to the far left side of the window.

lua/symbols-outline/config.lua

@@ -19,6 +19,7 @@ M.defaults = {
   autofold_depth = nil,
   auto_unfold_hover = true,
   fold_markers = { '', '' },
+  wrap = true,
   keymaps = { -- These keymaps can be a string or a table for multiple keys
     close = { '<Esc>', 'q' },
     goto_location = '<Cr>',