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, 29 insertions, 0 deletions

diff --git a/docs/manual/ecm-kde-modules.7.rst b/docs/manual/ecm-kde-modules.7.rst
index b3dffd77..184458f9 100644
--- a/docs/manual/ecm-kde-modules.7.rst
+++ b/docs/manual/ecm-kde-modules.7.rst
@@ -7,6 +7,28 @@ ecm-kde-modules(7)
 
    .. contents::
 
+Introduction
+============
+
+Extra CMake Modules (ECM) provides several modules that provide default settings
+(like installation directories, compiler flags and other CMake options) aimed at
+software produced by the KDE modules; these are documented here. ECM also
+provides modules with more general functionality, documented in
+:manual:`ecm-modules(7)`, and ones that extend the functionality of the
+``find_package`` command, documented in :manual:`ecm-find-modules(7)`.
+
+To use these modules, you need to tell CMake to find the ECM package, and
+then add either ``${ECM_MODULE_PATH}`` or ``${ECM_KDE_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 other types of modules
+available.
+
 All KDE Modules
 ===============
 
@@ -16,3 +38,10 @@ All KDE Modules
 
    /kde-module/*
 
+.. only:: man
+
+  See Also
+  ========
+
+  :manual:`ecm(7)`, :manual:`ecm-modules(7)`, :manual:`ecm-find-modules(7)`
+