chore: trigger docs deploy (gnolang#1801)

This trigger the github action `netlify.yml` on
[gnolang/docs.gno.land](https://github.com/gnolang/docs.gno.land) when a
merge is done on master and the docs/ folder have updates.

I will need someone (cc: @moul ) to create and add a PAT to this repo
secret 🙏🏼

EDIT:

This PR: 

- Bring a dev env for the docs.
- Add github action to call gnolang/docs.gno.land netlify deploy action

I'm currently working on a netlify preview, but it's a bit more complexe
than expected, it will come in another PR.

<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [ ] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [ ] Updated the official documentation or not needed
- [ ] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [ ] Added references to related issues and PRs
- [ ] Provided any useful hints for running manual tests
- [ ] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

.github/workflows/deploy-docs.yml

@@ -0,0 +1,22 @@
+name: deploy docs on gnolang/docs.gno.land repository
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - "docs/**"
+
+jobs:
+  trigger-netlify-docs-deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v6
+        with:
+          github-token: ${{ secrets.DOCS_DEPLOY_PAT }}
+          script: |
+            await github.rest.actions.createworkflowDispatch({
+                owner: 'gnolang',
+                repo: 'docs.gno.land',
+                workflow_id: 'netlify.yml',
+                ref: 'main'
+            })