feat: generate API reference docs with typedoc (#270)

auto generate markdown API reference docs from JSDoc comments using
typedoc to have an embedded docs inside node_modules. This allows AI
agent skills to point to `node_modules/axiom/dist/docs/ ` for a version
matched API reference

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: this only changes the build pipeline and dev dependencies to
generate packaged docs, without touching runtime/library logic.
> 
> **Overview**
> **Adds auto-generated API reference docs to the `axiom` package
build.** The `packages/ai` `build` script now runs `typedoc` to emit
markdown docs into `dist/docs`.
> 
> Introduces `typedoc.json` to define the public entry points to
document and configures markdown output (no readme, excludes
private/internal/external symbols). Adds `typedoc` +
`typedoc-plugin-markdown` dev dependencies and updates `pnpm-lock.yaml`
accordingly.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
1772b5a. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: aisha331

packages/ai/package.json

@@ -10,7 +10,7 @@
   ],
   "scripts": {
     "dev": "tsup --watch",
-    "build": "tsup && chmod +x dist/bin.js && pnpm check:vitest-entrypoints",
+    "build": "tsup && chmod +x dist/bin.js && typedoc && pnpm check:vitest-entrypoints",
     "check:vitest-entrypoints": "node ./scripts/check-vitest-entrypoints.mjs",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
@@ -126,6 +126,8 @@
     "prettier": "catalog:",
     "tinyrainbow": "^2.0.0",
     "tsup": "catalog:",
+    "typedoc": "^0.28.17",
+    "typedoc-plugin-markdown": "^4.10.0",
     "typescript": "catalog:",
     "vitest": "catalog:",
     "zod": "catalog:"

packages/ai/typedoc.json

@@ -0,0 +1,22 @@
+{
+  "$schema": "https://typedoc.org/schema.json",
+  "entryPoints": [
+    "src/index.ts",
+    "src/evals.ts",
+    "src/evals/scorers.ts",
+    "src/evals/aggregations.ts",
+    "src/evals/online.ts",
+    "src/config.ts",
+    "src/feedback.ts"
+  ],
+  "tsconfig": "tsconfig.build.json",
+  "plugin": ["typedoc-plugin-markdown"],
+  "out": "dist/docs",
+  "readme": "none",
+  "disableSources": true,
+  "excludePrivate": true,
+  "excludeInternal": true,
+  "excludeExternals": true,
+  "hideGenerator": true,
+  "includeVersion": true
+}