unity: add page (#23533)

Co-authored-by: Managor <42655600+Managor@users.noreply.github.com>
Co-authored-by: Ivan Baluta <ivanbaluta.dev@gmail.com>

pages/common/unity.md

@@ -0,0 +1,24 @@
+# unity
+
+> A tool for installing and managing Unity Editors, projects, and modules.
+> More information: <https://docs.unity.com/en-us/unity-cli/unity-cli-reference>.
+
+- Install a specific version of the Unity Editor:
+
+`unity {{[i|install]}} "{{unity_version}}"`
+
+- Log in to your Unity account:
+
+`unity {{[a|auth]}} login`
+
+- Install modules interactively:
+
+`unity {{[im|install-modules]}}`
+
+- Create a new Universal Render Pipeline 2D project:
+
+`unity {{[p|projects]}} new "{{project_name}}" --template com.unity.template.universal-2d --path "{{path/to/parent_directory}}"`
+
+- Open an existing project:
+
+`unity open "{{path/to/project_directory}}"`