Help: Add cmake-developer.7 manual

Add the manual with just an introduction section.  Leave section headers
for Help and Modules to be filled in later.

Help/index.rst

@@ -20,6 +20,7 @@ CMake Reference Documentation
    /manual/cmake-properties.7
    /manual/cmake-variables.7
    /manual/cmake-generator-expressions.7
+   /manual/cmake-developer.7
 
 .. only:: html
 

Help/manual/cmake-developer.7.rst

@@ -0,0 +1,18 @@
+cmake-developer(7)
+******************
+
+.. only:: html or latex
+
+   .. contents::
+
+Introduction
+============
+
+This manual is intended for reference by developers modifying the CMake
+source tree itself.
+
+Help
+====
+
+Modules
+=======

Utilities/Sphinx/conf.py.in

@@ -40,6 +40,7 @@ man_pages = [
     ('manual/cmake-properties.7', 'cmake-properties', 'CMake Properties Reference', [], 7),
     ('manual/cmake-variables.7', 'cmake-variables', 'CMake Variables Reference', [], 7),
     ('manual/cmake-generator-expressions.7', 'cmake-generator-expressions', 'CMake Generator Expressions', [], 7),
+    ('manual/cmake-developer.7', 'cmake-developer', 'CMake Developer Reference', [], 7),
 ]
 man_show_urls = False