atoum: add page (#3024)

* atoum: add page

* atoum: update example tokens for filenames

pages/common/atoum.md

@@ -0,0 +1,36 @@
+# atoum
+
+> A simple, modern and intuitive unit testing framework for PHP.
+> Homepage: <https://atoum.org>.
+
+- Initialise a configuration file:
+
+`atoum --init`
+
+- Run all tests:
+
+`atoum`
+
+- Run tests using the specified configuration file:
+
+`atoum -c {{path/to/file}}`
+
+- Run a specific test file:
+
+`atoum -f {{path/to/file}}`
+
+- Run a specific directory of tests:
+
+`atoum -d {{path/to/directory}}`
+
+- Run all tests under a specific namespace:
+
+`atoum -ns {{namespace}}`
+
+- Run all tests with a specific tag:
+
+`atoum -t {{tag}}`
+
+- Load a custom bootstrap file before running tests:
+
+`atoum --bootstrap-file {{path/to/file}}`