readme: inline a few tips

readme.md

@@ -24,3 +24,23 @@ nix build .#imgs.lappy
 this can then be `dd`'d onto a disk and directly booted from a EFI system.
 there's some post-processing to do before running a rebuild on the deployed system (e.g. change fstab UUIDs)
 refer to flake.nix for more details
+
+
+# admin tips
+
+online: <https://nixos.wiki/wiki/Cheatsheet>
+
+verify ALL nix store contents with:
+```sh
+sudo nix-store --verify --check-contents  # add the --repair flag to auto-repair as well
+```
+
+search for a package with:
+```sh
+nix search nixpkgs <query string>
+```
+
+find which package owns some file with:
+```sh
+nix-locate /bin/vim  # or any other package-relative path
+```