Add filesystem content (#1864)

* Update 104-file-system.md

* Update content/roadmaps/102-devops/content/101-os-concepts/104-file-system.md

Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/102-devops/content/101-os-concepts/104-file-system.md

@@ -1 +1,6 @@
-# File system
+# File System
+
+A file is a named collection of related information recorded on secondary storage such as magnetic disks, magnetic tapes, and optical disks. Generally, a file is a sequence of bits, bytes, lines, or records whose meaning is defined by the file's creator and user.
+
+<ResourceGroupTitle>Free Content</ResourceGroupTitle>
+<BadgeLink colorScheme='yellow' badgeText='Read' href='https://www.tutorialspoint.com/operating_system/os_file_system.htm'>Operating System - File System</BadgeLink>