Add NFS client packages (nfs-common on Debian, nfs-utils on Alpine)

Needed for NFS mounts. Included in the best-effort CLI tools list so a
missing/conflicting package never aborts the bootstrap. README + header
updated.

README.md

@@ -54,7 +54,9 @@ git clone git@git.ivanch.me:ivanch/dotfiles.git /tmp/dotfiles && \
 The installer:
 
 1. Detects the OS / package manager (`apt` on Debian, `apk` on Alpine) and
-   installs `git curl zsh vim` plus `htop` and `fzf`.
+   installs `git curl wget zsh vim`, plus CLI tools `htop`, `fzf`, `nslookup`
+   (dnsutils/bind-tools) and the NFS client (`nfs-common`/`nfs-utils` for
+   NFS mounts). `kubectl` is installed if available in the repos.
 2. Installs oh-my-zsh (unattended) + the `zsh-autosuggestions` plugin.
 3. Copies the `servers/` dotfiles into `$HOME`.
 4. Clones the Vim plugins declared in `.vimrc` (dracula, lightline,