chore: include documentation/ directory in npm publish (#1351)

## 🧰 Changes

i was reading through [this blog post](https://leerob.com/docs), which
pointed out that including docs in your `node_modules` is a generally
good DX practice (for both LLMs and humans) that have `rdme` installed
locally.

this PR ensures that our documentation is published to NPM!

## 🧬 QA & Testing

confirmed that it'll be included by running `npm pack` locally.

<details>

<summary>before</summary>

<img width="1616" height="4197" alt="CleanShot 2025-09-29 at 12 51
21@2x"
src="https://github.com/user-attachments/assets/a0d3c4f8-f42b-4c5f-a282-539fedd4e03c"
/>

</details>


<details>

<summary>after</summary>


<img width="1616" height="3693" alt="CleanShot 2025-09-29 at 12 50
41@2x"
src="https://github.com/user-attachments/assets/6fee653b-c459-446e-b240-0556734f9fdf"
/>

</details>

Author: kanadgupta

package.json

@@ -13,6 +13,7 @@
   "files": [
     "/bin/run*",
     "/dist",
+    "/documentation",
     "/oclif.manifest.json"
   ],
   "keywords": [