docs: rewrite demo tape — 7-scene "what can I do" narrative

Scenes: vim . dashboard, fuzzy find, ripgrep, run file, sidebar
toggle, git status, cheat sheet. Optional LSP section commented out.

.github/demo.tape

@@ -1,47 +1,94 @@
+# chopsticks demo — "what can I do with this?"
+# Record: cd ~/.vim && vhs .github/demo.tape
+#
+# Setup: mkdir -p /tmp/demo-project && cd /tmp/demo-project
+#   Create app.py, utils.py, config.yaml (small Python project)
+#   git init && git add -A && git commit -m "init"
+#
+# Optional LSP: open a .py file in vim, run :LspInstallServer
+#   then uncomment the LSP section below
+
 Output .github/demo.gif
 Set Shell bash
 Set FontSize 14
-Set Width 960
-Set Height 540
+Set Width 1080
+Set Height 620
 Set Theme "Builtin Solarized Dark"
-Set TypingSpeed 50ms
+Set TypingSpeed 40ms
 Set Padding 10
 
-Type "vim ~/.vim/modules/core.vim"
+# ── 1. Open project — sidebar + dashboard ──────────────────────────────────
+Type "cd /tmp/demo-project && vim ."
 Enter
-Sleep 1.5s
+Sleep 2.5s
 
-# Show the code with solarized theme and statusline
+# ── 2. Fuzzy find — instant file search ────────────────────────────────────
+Ctrl+p
+Sleep 0.8s
+Type "utils"
 Sleep 1s
+Enter
+Sleep 1.2s
 
-# Use Ctrl+p for fuzzy find
-Type "\x10"
-Sleep 1s
-Type "lsp"
+# ── 3. Ripgrep — search across entire project ──────────────────────────────
+Type ",rg"
+Sleep 0.8s
+Type "greet"
 Sleep 1s
 Escape
 Sleep 0.5s
 
-# Go to definition
-Type "gg"
-Sleep 0.3s
-Type "/mapleader"
+# ── 4. Run file — one keystroke ─────────────────────────────────────────────
+# open app.py first
+Ctrl+p
+Sleep 0.5s
+Type "app"
+Sleep 0.8s
 Enter
 Sleep 1s
-
-# Show cheat sheet
-Type ",?"
+Type ",cr"
 Sleep 2s
+Enter
+Sleep 0.5s
+
+# ── 5. File sidebar toggle ─────────────────────────────────────────────────
+Type ",e"
+Sleep 1.5s
+Type ",e"
+Sleep 0.8s
+
+# ── 6. Git status ──────────────────────────────────────────────────────────
+Type ",gs"
+Sleep 1.5s
 Type "q"
 Sleep 0.5s
 
-# Open file browser
-Type ",e"
-Sleep 1.5s
-Escape
+# ── 7. Cheat sheet — discover everything ───────────────────────────────────
+Type ",?"
+Sleep 2.5s
+Type "q"
 Sleep 0.5s
 
-# Quit
+# ── done ────────────────────────────────────────────────────────────────────
 Type ":qa!"
 Enter
 Sleep 0.5s
+
+# ── (optional) LSP — uncomment after :LspInstallServer in a .py file ──────
+# Ctrl+p
+# Sleep 0.5s
+# Type "utils"
+# Sleep 0.8s
+# Enter
+# Sleep 1.5s
+# Type "/greet"
+# Enter
+# Sleep 0.5s
+# Type "K"
+# Sleep 2s
+# Escape
+# Sleep 0.5s
+# Type "gd"
+# Sleep 1.5s
+# Ctrl+o
+# Sleep 0.8s