docs(docs): add drydock documentation and update tools index

docs/tools/drydock.mdx

@@ -0,0 +1,22 @@
+---
+title: drydock
+description: drydock fleet view of uncommitted, unpushed, and unreleased work, scanning the ghq root.
+---
+
+drydock lists what is uncommitted, unpushed, and unreleased across every repo under its roots.
+
+| | |
+| --- | --- |
+| Source | `dot_config/drydock/config.toml` |
+| Target | `~/.config/drydock/config.toml` (holds live beside it in `holds.toml`, unmanaged) |
+| Packages | Not declared in `packages.yaml`; installed with cargo (`~/.cargo/bin/drydock`) |
+
+## config.toml
+
+```toml ~/.config/drydock/config.toml
+roots = ["~/Code"]
+```
+
+Only `roots` is set; everything else stays at drydock's defaults (`drydock config show` prints the effective config). The root is the ghq root, where repos sit at `<host>/<owner>/<repo>`, within the default `max_depth = 4`. `~/Projects` would find nothing: it holds only symlinks (made by [`projects-sync`](/shell/scripts#projects-sync)), and drydock does not follow symlinks by default (`follow_symlinks = false`).
+
+`drydock --root <path>` replaces the configured roots for one run.