update binder path to open to examples folder

Author: DenisaCG

.github/workflows/binder-on-pr.yml

@@ -21,7 +21,7 @@ jobs:
               issue_number: context.issue.number,
               owner: context.repo.owner,
               repo: context.repo.repo,
-              body: `[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/${PR_HEAD_USERREPO}/${PR_HEAD_REF}?urlpath=lab) :point_left: Launch a Binder on branch _${PR_HEAD_USERREPO}/${PR_HEAD_REF}_`
+              body: `[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/${PR_HEAD_USERREPO}/${PR_HEAD_REF}?urlpath=lab/tree/examples/example.jpblockly) :point_left: Launch a Binder on branch _${PR_HEAD_USERREPO}/${PR_HEAD_REF}_`
             })
         env:
           PR_HEAD_REF: ${{ github.event.pull_request.head.ref }}

README.md

@@ -2,7 +2,7 @@
 
 [![Github Actions Status](https://github.com/QuantStack/jupyterlab-blockly/actions/workflows/build.yml/badge.svg)](https://github.com/quantstack/jupyterlab-blockly/actions/workflows/build.yml)
 [![lite-badge](https://jupyterlite.rtfd.io/en/latest/_static/badge-launch.svg)](https://jupyterlab-blockly.readthedocs.io/en/latest/lite/lab/index.html?path=example.jpblockly)
-[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/quantstack/jupyterlab-blockly/main?urlpath=lab)
+[![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/quantstack/jupyterlab-blockly/main?urlpath=lab/tree/examples/example.jpblockly)
 
 
 Blockly extension for JupyterLab.