getcap: add page (#8578)

* Add getcap page for Linux OS

* Update getcap.md

* Update link to manned

pages/linux/getcap.md

@@ -0,0 +1,12 @@
+# getcap
+
+> Command to display the name and capabilities of each specified file.
+> More information: <https://manned.org/getcap>.
+
+- Get capabilities for the given files:
+
+`getcap {{path/to/file1 path/to/file2 ...}}`
+
+- Displays all searched entries even if no capabilities are set:
+
+`getcap -v {{path/to/file1 path/to/file2 ...}}`