small update

modules/system/nix/documentation.mod.nix

@@ -0,0 +1,31 @@
+{
+  # faster rebuilding
+  documentation = {
+    # whether to enable the `doc` output of packages
+    # generally in ${pkg}/share/ as plaintext or html
+    # can shave off a few megabytes
+    doc.enable = false;
+
+    # whether to install the `info` command and the `info`
+    # output of packages
+    info.enable = false;
+
+    # Whether to install documentation targeted at developers.
+    dev.enable = true;
+
+    man = {
+      # Whether to install manual pages
+      # this means packages that provide a `man` output will have said output
+      # included in the final closure
+      enable = true;
+
+      # Whether to generate the manual page index caches
+      # if true, it becomes possible to search for a page or keyword
+      # using utilities like apropos(1) and the -k option of man(1).
+      generateCaches = false;
+
+      # Whether to enable mandoc as the default man page viewer.
+      mandoc.enable = false; # my default manpage viewer is bat, so this isn't necessary
+    };
+  };
+}