dcg: add page (#4412)

pages/common/dcg.md

@@ -0,0 +1,16 @@
+# dcg
+
+> Drupal code generator.
+> More information: <https://github.com/Chi-teck/drupal-code-generator>.
+
+- Start a wizard to choose what kind of code (e.g. module, service, form, etc.) to generate:
+
+`dcg`
+
+- Directly specify the kind of code to generate:
+
+`dcg {{service|plugin|theme|module|form}}`
+
+- Generate the code in a specific directory:
+
+`dcg --directory {{path/to/directory}}`