Improve the manuals

This adds an ecm-developer manual that replaces writing-find-modules.md
(a lot of which was upstreamed to CMake's own documentation). It also
adds introductory text to the ecm-*-modules manuals.

1 files changed, 31 insertions, 0 deletions

diff --git a/docs/manual/ecm-modules.7.rst b/docs/manual/ecm-modules.7.rst
index 70b09f5e..16fd8612 100644
--- a/docs/manual/ecm-modules.7.rst
+++ b/docs/manual/ecm-modules.7.rst
@@ -7,6 +7,30 @@ ecm-modules(7)
 
    .. contents::
 
+Introduction
+============
+
+Extra CMake Modules (ECM) provides various modules that provide useful functions
+for CMake scripts. ECM actually provides three types of modules: those that
+extend the functionality of the ``find_package`` command are documented in
+:manual:`ecm-find-modules(7)`; those that provide standard settings for software
+produced by the KDE community are documented in :manual:`ecm-kde-modules(7)`.
+The rest provide macros and functions for general use by CMake scripts and are
+documented here.
+
+To use these modules, you need to tell CMake to find the ECM package, and
+then add either ``${ECM_MODULE_PATH}`` or ``${ECM_MODULE_DIR}`` to the
+``CMAKE_MODULE_PATH`` variable:
+
+.. code-block:: cmake
+
+  find_package(ECM REQUIRED NO_MODULE)
+  set(CMAKE_MODULE_PATH ${ECM_MODULE_DIR})
+
+Using ``${ECM_MODULE_PATH}`` will also make the find modules and KDE modules
+available.
+
+
 All Modules
 ===========
 
@@ -16,3 +40,10 @@ All Modules
 
    /module/*
 
+.. only:: man
+
+  See Also
+  ========
+
+  :manual:`ecm(7)`, :manual:`ecm-find-modules(7)`, :manual:`ecm-kde-modules(7)`
+