chflags: add page (#2682)

pages/osx/chflags.md

@@ -0,0 +1,19 @@
+# chflags
+
+> Change file or directory flags.
+
+- Set the `hidden` flag for a file:
+
+`chflags {{hidden}} {{path/to/file}}`
+
+- Unset the `hidden` flag for a file:
+
+`chflags {{hidden}} {{path/to/file}}`
+
+- Recursively set the `uchg` flag for a directory:
+
+`chflags -R {{uchg}} {{path/to/directory}}`
+
+- Recursively unset the `uchg` flag for a directory:
+
+`chflags -R {{nouchg}} {{path/to/directory}}`