feat: add link to sitemap (#5)

### Explanation

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### Issue

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### Attestations

- [x] I have read and agree to the [Code of Conduct](https://docs.nhcarrigan.com/community/coc/)
- [x] I have read and agree to the [Community Guidelines](https://docs.nhcarrigan.com/community/guide/).
- [x] My contribution complies with the [Contributor Covenant](https://docs.nhcarrigan.com/dev/covenant/).

### Dependencies

- [ ] I have pinned the dependencies to a specific patch version.

### Style

- [x] I have run the linter and resolved any errors.
- [x] My pull request uses an appropriate title, matching the conventional commit standards.
- [x] My scope of feat/fix/chore/etc. correctly matches the nature of changes in my pull request.

### Tests

- [ ] My contribution adds new code, and I have added tests to cover it.
- [ ] My contribution modifies existing code, and I have updated the tests to reflect these changes.
- [ ] All new and existing tests pass locally with my changes.
- [ ] Code coverage remains at or above the configured threshold.

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Reviewed-on: #5
Co-authored-by: Naomi Carrigan <commits@nhcarrigan.com>
Co-committed-by: Naomi Carrigan <commits@nhcarrigan.com>

.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+    "sonarlint.connectedMode.project": {
+        "connectionId": "Naomi",
+        "projectKey": "docs"
+    }
+}

src/components/navigation.ts

@@ -142,5 +142,12 @@ export const navigation = [
         link: "/misc/music",
       }
     ]
+  },
+  {
+    label: "Sitemap",
+    link: "https://sitemap.nhcarrigan.com",
+    attrs: {
+      target: "_blank",
+    }
   }
 ];