Add external link to /proc File System (#8385)

* Update 101-listing-finding-proc.md

Append useful article at the end.

* Update 101-listing-finding-proc.md

Small change.

---------

Co-authored-by: Liwei Su <liweisu@proton.me>

src/data/roadmaps/linux/content/106-process-management/101-listing-finding-proc.md

@@ -22,4 +22,8 @@ Exploring the proc directory (`/proc`), we dive even deeper, enabling us to view
 # view specifics of a particular PID
 cat /proc/{PID}/status
 ```
-In short, 'Finding and Listing Processes (proc)' in Linux is not just a core aspect of process management, but also a necessary skill for enhancing system performance and resolution of issues.
+In short, 'Finding and Listing Processes (proc)' in Linux is not just a core aspect of process management, but also a necessary skill for enhancing system performance and resolution of issues.
+
+Visit the following resources to learn more:
+
+- [@article@The /proc File System](https://www.kernel.org/doc/html/latest/filesystems/proc.html)