treewide: modules -> profiles, separate dirs, list in README (#29)

Enforce proper naming: all paths are lowercase and hyphen-separated,
if there's a line of models (aspire, macbook-pro, thinkpad) it becomes
a subdirectory. Documentation for profiles is moved to README files in
respective directories.

Add an Org mode table that lists all available profiles and their paths.

Instead of fetching repo locally, use a Nix channel. Making hardware
profiles read-only should improve quality and amount of participation
long-term.

lenovo/thinkpad/x220/default.nix

@@ -0,0 +1,22 @@
+{ config, pkgs, ... }:
+
+{
+  imports = [ ../intel.nix ];
+
+  # TPM chip countains a RNG
+  security.rngd.enable = true;
+
+  boot = {
+    kernelModules = [ "tp_smapi" ];
+    extraModulePackages = with config.boot.kernelPackages; [ tp_smapi ];
+  };
+
+  # hard disk protection if the laptop falls
+  services.hdapsd.enable = true;
+
+  # fingerprint reader: login and unlock with fingerprint (if you add one with `fprintd-enroll`)
+  #services.fprintd.enable = true;
+  #security.pam.services.login.fprintAuth = true;
+  #security.pam.services.xscreensaver.fprintAuth = true;
+  # similarly for other PAM providers
+}