docs(worktrees): add nested worktreeinclude reference

public-docs/worktrees/worktreeinclude.md

@@ -0,0 +1,61 @@
+---
+title: .worktreeinclude
+description: Copy gitignored local files into new Paseo worktrees.
+nav: .worktreeinclude
+order: 12
+category: Workspaces
+---
+
+# .worktreeinclude
+
+Add `.worktreeinclude` at the root of your source checkout to copy local configuration into new [Git worktrees](/docs/worktrees). Paseo copies matching gitignored files before setup, terminals, and the first Agent start.
+
+## Copy your local configuration
+
+For a project whose `.gitignore` includes `.env` and `config/*.local.json`, create this `.worktreeinclude`:
+
+```gitignore
+.env
+config/*.local.json
+```
+
+When you create a worktree through Paseo, an existing `.env` and matching files such as `config/dev.local.json` are copied to the same relative paths in the new worktree. Their contents stay out of Git.
+
+Commit `.worktreeinclude` to share the patterns with your team. Each teammate supplies their own ignored files in the checkout they create worktrees from.
+
+## Pattern syntax
+
+Use gitignore syntax, with one pattern per line. Comments start with `#`. Prefix a pattern with `!` to exclude a match:
+
+```gitignore
+# Local environment and configuration
+.env
+config/*.local.json
+!config/production.local.json
+```
+
+A pattern only selects files that Git already ignores. Adding a path here does not ignore it, so also configure `.gitignore` when needed. Tracked files and untracked files that Git does not ignore are excluded.
+
+## When files are copied
+
+The built-in `worktree-include` plugin reads the file from the checkout you create the worktree from. That source can itself be another worktree. Keep the plugin enabled for copying to run.
+
+- Without `.worktreeinclude`, the plugin copies nothing.
+- Matching files must exist in the source checkout.
+- Existing destination files are skipped, preserving their contents.
+- Copies happen during creation, with no ongoing synchronization between checkouts.
+- A copy error aborts creation and removes the new worktree. Avoid including symlinked directories or nested repositories, which cannot be copied as files.
+
+## Run commands during setup
+
+Use `.worktreeinclude` for files that already exist locally. Use a [setup hook](/docs/worktrees#setup-and-teardown) to install dependencies, generate files, or fetch secrets:
+
+```json
+{
+  "worktree": {
+    "setup": "npm ci"
+  }
+}
+```
+
+Put this configuration in `paseo.json` on the base branch used for the new worktree. Copied files are available when setup runs.