openpgp-card-tools: Add shell completions and man pages

This patch adds a postInstall step to generate and install shell
completions and man pages as described in the project readme:
https://codeberg.org/openpgp-card/openpgp-card-tools/src/tag/v0.11.7#system-integration

pkgs/by-name/op/openpgp-card-tools/package.nix

@@ -2,6 +2,7 @@
 , stdenv
 , rustPlatform
 , fetchFromGitea
+, installShellFiles
 , pkg-config
 , pcsclite
 , dbus
@@ -24,7 +25,7 @@ rustPlatform.buildRustPackage rec {
 
   cargoHash = "sha256-G5+lVK41hbzy/Ltc0EKoUfqF0M1OYu679jyVjYKJmn0=";
 
-  nativeBuildInputs = [ pkg-config rustPlatform.bindgenHook ];
+  nativeBuildInputs = [ installShellFiles pkg-config rustPlatform.bindgenHook ];
 
   buildInputs = [ pcsclite dbus ] ++ lib.optionals stdenv.hostPlatform.isDarwin [
     darwin.apple_sdk.frameworks.PCSC
@@ -37,6 +38,13 @@ rustPlatform.buildRustPackage rec {
     };
   };
 
+  postInstall = ''
+    OCT_COMPLETION_OUTPUT_DIR=$PWD/shell $out/bin/oct
+    installShellCompletion ./shell/oct.{bash,fish} ./shell/_oct
+    OCT_MANPAGE_OUTPUT_DIR=$PWD/man $out/bin/oct
+    installManPage ./man/*.1
+  '';
+
   meta = with lib; {
     description = "Tool for inspecting and configuring OpenPGP cards";
     homepage = "https://codeberg.org/openpgp-card/openpgp-card-tools";