Add Telescope configuration, update python versions and pin gitsigns version

templates/nvim/lua/telescope.lua.j2

@@ -0,0 +1,10 @@
+local telescope = require('telescope');
+
+telescope.setup({
+  defaults = {
+    layout_strategy = 'vertical',
+    layout_config = {
+      vertical = { width = 0.5, height = 0.7 }
+    },
+  },
+})