squash: add more warnings

docs/plugins.rst.j2

@@ -14,6 +14,18 @@
 {{ PLUGIN_ID }}
 {{ '^' * (PLUGIN_ID | length)}}
 
+{#
+    TODO: once we start getting reviewed and polished plugins, drop the warning
+    for those that would be done and ready. Probably with some temporary list
+    to which we would add their names.
+#}
+.. warning::
+
+    Please, be aware that the documentation below is a work in progress. We are
+    working on fixing it, adding missing bits and generally making it better.
+    Also, it was originaly used for command line help only, therefore the
+    formatting is often suboptional.
+
 {% if PLUGIN.__doc__ %}
 {{ PLUGIN.__doc__ | dedent | strip }}
 {% endif %}