zm: add page (#6355)

pages/common/zm.md

@@ -0,0 +1,16 @@
+# zm
+
+> A tool for managing articles of newspapers and blogs.
+> More information: <https://github.com/ZERMZeitung/zm2>.
+
+- Make a new draft:
+
+`zm new`
+
+- Edit a draft:
+
+`zm edit`
+
+- Publish a draft and commit it with git:
+
+`zm publish`