docs(readme): add Initialize Projects snippet to Get Started (#145)

The top-level Get Started section showed the install command but not
the per-project init step. Adding the same `cd your-project /
codegraph init -i` block that lives in Quick Start so users see the
full happy path before scrolling.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

README.md

@@ -26,6 +26,13 @@ npx @colbymchenry/codegraph
 
 ![1_C_VYnhpys0UHrOuOgpgoyw](https://github.com/user-attachments/assets/f168182f-4d9a-44e0-94d7-08d018cc8a3a)
 
+#### Initialize Projects
+
+```bash
+cd your-project
+codegraph init -i
+```
+
 </div>
 
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