rubocop: add page

pages/osx/rubocop.md

@@ -0,0 +1,31 @@
+# rubocop
+
+> Lint Ruby files.
+
+- Check all files in the current directory:
+
+`rubocop`
+
+- Check specific files or directories:
+
+`rubocop {{path_1}} {{path_2}}`
+
+- Write output to file:
+
+`rubocop --out {{file}}`
+
+- View list of cops:
+
+`rubocop --show-cops`
+
+- Exclude a cop:
+
+`rubocop --except {{cop_1}} {{cop_2}}`
+
+- Run only specified cops:
+
+`rubocop --only {{cop_1}} {{cop_2}}`
+
+- Auto-correct files (experimental):
+
+`rubocop --auto-correct`