added readlink

pages/common/readlink.md

@@ -0,0 +1,11 @@
+# readlink
+
+> Follow symlinks and get symlink information.
+
+- Get the actual file to which the symlink points:
+
+`readlink {{filename}}`
+
+- Get the absolute path to a file:
+
+`readlink -f {{filename}}`