minor CONTRIBUTING.md updates

.github/CONTRIBUTING.md

@@ -166,27 +166,37 @@ After submitting a pull request, please make sure to sign [our CLA (Contributor
 <br/>
 
 ## :wrench: Troubleshooting
+
 Below are some common errors and their possible fixes. Please feel free to open an issue if none of these suggested fixes work.
 
-1. **ERR_CERT_AUTHORITY_INVALID**
+<details>
+  <summary>**ERR_CERT_AUTHORITY_INVALID** in the browser's console</summary>
 
 This error happens when content is not loaded and the browser's console displays the `ERR_CERT_AUTHORITY_INVALID` error message.
 
-That's because you're using a self-signed certificate for development and your browser does not allow those.
-
+It usually happens because you're using a self-signed certificate for development and your browser probably does not allow those yet.
 
 If you're using Chrome, open a new tab and access `chrome://flags/#allow-insecure-localhost`. Then enable this flag. If you're using another browser, please look for similar options if needed.
 
-2. **Jupyter permissions issue on Linux/WSL**
-If you're running Jupyter on Linux/WSL and encounter the following error:
+</details>
+
+<details>
+  <summary>**Jupyter permissions issue on Linux/WSL**</summary>
+
+This error usually manifests as the following message:
 
+```
 RuntimeError: Permissions assignment failed for secure file: '/home/jupyteruser/.local/share/jupyter/runtime/jpserver-8.json'. Got '0o677' instead of '0o0600'.
+```
 
-This typically means that the folder doesn't exist or that the user doesn't have the required permissions. To fix this issue, update the permissions as in the example below.
+This message typically means that the folder doesn't exist or that the user doesn't have the required permissions. To fix this issue, update the permissions as in the example below.
 
 ```bash
 mkdir -p ./jupyterfiles
 sudo chown -R $(whoami):$(whoami) ./jupyterfiles
 mkdir -p ./jupyterfiles/.local/share/jupyter
 ```
-After running the above commands, restart the Jupyter server container to apply the changes. 
+
+After running the commands above, restart the Jupyter server container to apply the changes.
+
+</details>