Fix README: add --no-timeout, --output-format diff, thinktank init (#154)

Fixes found by thinktank ensemble (3/3 agents, 89% convergence):
- Add missing --no-timeout flag to run command table
- Update --output-format to include diff option
- Add thinktank init command section
- Remove duplicate init entry

Co-authored-by: unknown <that-github-user@github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 3 people

README.md

@@ -143,10 +143,15 @@ Run N parallel agents on a task.
 | `--threshold <number>` | Convergence clustering similarity threshold, 0.0–1.0 (default: 0.3) |
 | `--whitespace-insensitive` | Ignore whitespace in convergence comparison |
 | `--retry` | Re-run only failed/timed-out agents from the last run |
-| `--output-format <fmt>` | Output format: `text` (default) or `json` |
+| `--no-timeout` | Disable agent timeout entirely |
+| `--output-format <fmt>` | Output format: `text` (default), `json`, or `diff` |
 | `--no-color` | Disable colored output |
 | `--verbose` | Show detailed agent output |
 
+### `thinktank init`
+
+Set up thinktank in the current project — checks prerequisites and detects your test command.
+
 ### `thinktank apply`
 
 Apply the recommended agent's changes to your working tree.