Add overseer extension. (#828)

* Add overseer ext.

* chore: autogen (vimdocs+formating)

Co-authored-by: dcordb <dcordb@users.noreply.github.com>

lua/lualine/extensions/overseer.lua

@@ -0,0 +1,16 @@
+-- Copyright (c) 2020-2021 hoob3rt
+-- MIT license, see LICENSE for more details.
+
+local M = {}
+
+M.sections = {
+  lualine_a = {
+    function()
+      return 'OverseerList'
+    end,
+  },
+}
+
+M.filetypes = { 'OverseerList' }
+
+return M