Update README benchmarks with show command and latest numbers

Added show to both speed and token tables. Updated all numbers from
fresh hyperfine runs. Log is honestly reported as slightly slower
than git (~0.8x) - libgit2 revwalk has overhead on small repos.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: fielding

README.md

@@ -18,17 +18,19 @@ Measured with [hyperfine](https://github.com/sharkdp/hyperfine), 100 runs, Relea
 
 | Command | git equivalent | git | nit | Speedup |
 |---|---|---|---|---|
-| `status` | `git status --porcelain -b` | 11.3 ms | 7.6 ms | **1.49x faster** |
-| `diff` | `git diff -U1` | 11.2 ms | 8.1 ms | **1.38x faster** |
-| `log -20` | `git log -20 --oneline` | 6.5 ms | 6.6 ms | ~1x (parity) |
+| `status` | `git status --porcelain -b` | 13.7 ms | 8.4 ms | **1.64x faster** |
+| `diff` | `git diff -U1` | 14.3 ms | 9.9 ms | **1.44x faster** |
+| `show` | `git show` | 10.2 ms | 7.3 ms | **1.39x faster** |
+| `log -20` | `git log -20 --oneline` | 7.7 ms | 9.5 ms | ~0.8x (slower) |
 
 ### Token savings (nit default vs git default)
 
 | Command | `git` default | `nit` default | Savings |
 |---|---|---|---|
-| `status` | ~116 tokens | ~30 tokens | **74%** |
+| `status` | ~125 tokens | ~36 tokens | **71%** |
 | `log -20` | ~2,273 tokens | ~301 tokens | **87%** |
-| `diff` | ~942 tokens | ~622 tokens | **34%** |
+| `diff` | ~1,016 tokens | ~657 tokens | **35%** |
+| `show` | ~20,583 tokens | ~19,737 tokens | **4%** |
 
 *Token counts approximated at ~4 chars/token. Savings scale with repo size and dirty file count.*