feat(docs): add initial benchmark tables

README.md

@@ -22,6 +22,56 @@ your workflows such that you never have to worry about whether your
 > considered much more than a tech demo or proof of concept. Do not use in
 > production yet.
 
+### Benchmarks
+
+Even at this early stage, orogene is **very** fast. These benchmarks are all
+on ubuntu linux running under wsl2, with an ext4 filesystem.
+
+All benchmarks are ordered from fastest to slowest (lower is better):
+
+#### Warm Cache
+
+This test shows performance when running off a warm cache, with an existing
+lockfile. This scenario is common in CI scenarios with caching enabled, as
+well as local scenarios where `node_modules` is wiped out in order to "start
+over" (and potentially when switching branches).
+
+Of note here is the contrast between the subsecond (!) installation by
+orogene, versus the much more noticeable install times of literally everything
+else.
+
+| Package Manager | Mean [ms] | Min [ms] | Max [ms] | Relative |
+|:---|---:|---:|---:|---:|
+| `orogene` | 417.3 ± 43.3 | 374.6 | 524.8 | 1.00 |
+| `bun` | 1535.2 ± 72.5 | 1442.3 | 1628.9 | 3.68 ± 0.42 |
+| `pnpm` | 8285.1 ± 529.0 | 7680.4 | 9169.9 | 19.85 ± 2.42 |
+| `yarn` | 20616.7 ± 1726.5 | 18928.6 | 24401.5 | 49.41 ± 6.59 |
+| `npm` | 29132.0 ± 4569.2 | 25113.4 | 38634.2 | 69.81 ± 13.13 |
+
+#### Cold Cache
+
+This test shows performance when running off a cold cache, but with an
+existing lockfile. This scenario is common in CI scenarios that don't cache
+the package manager caches between runs, and for initial installs by
+teammates on relatively "clean" machines.
+
+| Package Manager | Mean [s] | Min [s] | Max [s] | Relative |
+|:---|---:|---:|---:|---:|
+| `bun` | 5.203 ± 1.926 | 3.555 | 9.616 | 1.00 |
+| `orogene` | 8.346 ± 0.416 | 7.938 | 9.135 | 1.60 ± 0.60 |
+| `pnpm` | 27.653 ± 0.467 | 26.915 | 28.294 | 5.31 ± 1.97 |
+| `npm` | 31.613 ± 0.464 | 30.930 | 32.192 | 6.08 ± 2.25 |
+| `yarn` | 72.815 ± 1.285 | 71.275 | 74.932 | 13.99 ± 5.19 |
+
+#### Caveat Emptor
+
+At the speeds at which orogene operates, these benchmarks can
+vary widely because they depend on the underlying filesystem's performance.
+For example, the gaps might be much smaller on Windows or (sometimes) macOS.
+They may even vary between different filesystems on Linux/FreeBSD. Note that
+orogene uses different installation strategies based on support for e.g.
+reflinking (btrfs, APFS, xfs).
+
 ### Building
 
 #### Requirements