Add warnings to Moire generated files.

CONTRIBUTING.md

@@ -1,3 +1,8 @@
+<!--
+    This is generated file.
+    Do not edit it manually, edit the Moire source file instead.
+-->
+
 Contributing
 ============
 

README.md

@@ -1,4 +1,7 @@
-
+<!--
+    This is generated file.
+    Do not edit it manually, edit the Moire source file instead.
+-->
 
 The **Map Machine** project consists of
 

doc/INSTALL.md

@@ -1,3 +1,8 @@
+<!--
+    This is generated file.
+    Do not edit it manually, edit the Moire source file instead.
+-->
+
 Install
 -------
 

doc/moi/readme.moi

@@ -1,5 +1,3 @@
-\title {Map Machine}
-
 The \b {Map Machine} project consists of
 
 \list

map_machine/doc/moire_manager.py

@@ -265,6 +265,18 @@ class MapMachineMarkdown(MapMachineMoire, DefaultMarkdown):
 
     images = {}
 
+    def body(self, arg: Arguments) -> str:
+        """Remove redundant new lines and add a warning."""
+        return (
+            "<!--\n"
+            "    This is generated file.\n"
+            "    Do not edit it manually, edit the Moire source file instead.\n"
+            "-->\n\n"
+            + self.parse(arg[0], in_block=True)
+            .replace("\n\n\n", "\n\n")
+            .replace("\n\n\n", "\n\n")
+        )
+
     def color(self, arg: Arguments) -> str:
         """Ignore colors in Markdown."""
         return self.clear(arg[0])