only smart-nav on gentoo, and not on other systems, same with tmux navigation

dot_config/nvim/lua/plugins/tmux.lua.tmpl

@@ -0,0 +1,19 @@
+{{ if ne .chezmoi.hostname "gentoo" }}
+return {
+  'alexghergh/nvim-tmux-navigation',
+  config = function()
+    require 'nvim-tmux-navigation'.setup {
+      disable_when_zoomed = false, -- defaults to false
+      keybindings = {
+        left = "<C-h>",
+        down = "<C-j>",
+        up = "<C-k>",
+        right = "<C-l>",
+        last_active = "<C-\\>",
+      }
+    }
+  end
+}
+{{ else }}
+return {}
+{{ end }}