docs: correct the README

README.md

@@ -1,8 +1,9 @@
 # prestobuntu
 
-A script to customize Ubuntu to my preferences. It is intended to be
-idempotent, so it's safe to run it multiple times; it will only apply the
-changes once.
+A script to customize Ubuntu to my preferences. Requires Ubuntu 22.04 or newer.
+
+Most steps check whether they have already been applied and skip themselves if
+so, but the script is not fully idempotent yet — see "Re-running" below.
 
 - Boot
   - Text instead of graphics
@@ -14,27 +15,28 @@ changes once.
   - Hard-code DNS to 1.1.1.1
   - Disable cups, whoopsie, apt-daily, automatic updates
 - Remote access
-  - openssh-server, with pre-install authorized keys
+  - openssh-server, with pre-installed authorized keys
   - tailscale
   - corkscrew (for tunnelling ssh over an http proxy)
 - Filesystem
   - Remove empty directories from /home/user
 - Install packages
-  - tmux, git, exuberant-ctags, fd, nodejs
+  - tmux, git, exuberant-ctags, ripgrep, fd, nodejs, kitty, syncthing
 - Neovim
-  - Plugins: vim-sensible, vim-fugitive, vim-commentary, vim-unimpaired,
-    supertab, ale, lightline, fzf, vim-gitgutter, vim-foldsearch, vim-ripgrep,
-    copilot.vim
+  - Plugin manager: lazy.nvim (bootstraps itself from `init.lua`)
+  - Plugins: which-key, neodev, vim-sensible, vim-sleuth, vim-fugitive,
+    vim-commentary, vim-unimpaired, supertab, ale, gruvbox.nvim, vim-airline,
+    vim-lastplace, vim-ripgrep, vim-gitgutter, undotree, vim-foldsearch, fzf,
+    mru, copilot.vim
 - Shell
   - zsh with prezto
 - User interface
   - Create Gruvbox dark profile for gnome-terminal and neovim
 
 ## Installation
 
-The installation script is auto-updating and has many safety checks. Of course,
-you should inspect and verify it before running (as one should do before
-running any arbitrary shell script from the Internet).
+Of course, you should inspect and verify the script before running it (as one
+should do before running any arbitrary shell script from the Internet).
 
 ### Installation from local file
 
@@ -43,6 +45,17 @@ running any arbitrary shell script from the Internet).
 
 ### Installation from Internet
 
-    wget https://raw.githubusercontent.com/presto8/prestobuntu/master/setup
+    wget https://raw.githubusercontent.com/presto8/prestobuntu/main/setup
     nano setup  # inspect and verify the script
     bash setup
+
+## Re-running
+
+Re-running `bash setup` on an already-provisioned machine currently fails in
+`setup_tmux`, which clones its tmux plugins unconditionally; under `set -e` the
+"already exists" error aborts the whole run. Remove
+`~/.config/tmux/plugins` first, or skip that step, until this is fixed.
+
+Config files (`init.lua`, `gitconfig`, `tmux.conf`, ...) are fetched from
+GitHub rather than taken from the local checkout, so editing them next to the
+script and re-running will *not* install your edits.