Doc: Describe how to declare files in projects

Including using OTHER_FILES for qmake projects.

Fixes: QTCREATORBUG-27157
Change-Id: I802000c90472464430d1335b9e962c6691cc567a
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

doc/qtcreator/src/editors/creator-locator.qdoc

@@ -230,9 +230,10 @@
 
     \endlist
 
-    If locator does not find some files, you can add them to the \c DISTFILES
-    variable in the \c .pro file to include them into the distribution tarball
-    of your project and thus make them known to \QC as well.
+    \if defined(qtcreator)
+    If locator does not find some files, see \l{Specifying Project Contents}
+    for how to make them known to the locator.
+    \endif
 
     \section1 Configuring Locator Filters
 

doc/qtcreator/src/editors/creator-only/creator-beautifier.qdoc

@@ -121,8 +121,7 @@
 
                 \li Select \uicontrol {Use file *.astylerc defined in project files}
                     or \uicontrol {Use file uncrustify.cfg defined in project files},
-                    to use the configuration file
-                    \l{Displaying Additional File Types in Projects View}
+                    to use the configuration file \l{Specifying Project Contents}
                     {defined in the project file} as the configuration file
                     for the selected tool.
 

doc/qtcreator/src/editors/creator-search.qdoc

@@ -142,6 +142,12 @@
 
                     \image qtcreator-search-allprojects.png
 
+                    \if defined(qtcreator)
+                    If you cannot find some files, see
+                    \l{Specifying Project Contents} for how
+                    to declare them as a part of the project.
+                    \endif
+
                 \li \uicontrol {Current Project} searches from the project you
                     are currently editing.
 

doc/qtcreator/src/linux-mobile/creator-deployment-embedded-linux.qdoc

@@ -56,6 +56,7 @@
     \section1 Adding Missing Files
 
     The process to add files to deploy depends on the build system you use.
+    For more information, see \l{Specifying Project Contents}.
 
     \section2 CMake Builds
 

doc/qtcreator/src/projects/creator-only/creator-projects-creating.qdoc

@@ -239,21 +239,33 @@
 
     \include creator-python-project.qdocinc python project wizards
 
-    \section1 Displaying Additional File Types in Projects View
+    \section1 Specifying Project Contents
+
+    A project can contain files that should be:
+
+    \list
+        \li Compiled or otherwise handled by the build
+        \li Installed
+        \li Not installed, but included in a source package created with
+            \c {make dist}
+        \li Not installed, nor be part of a source package, but still be known
+            to \QC
+    \endlist
 
     \QC displays all files that are declared to be part of the project by the
     project files in the \l Projects view. The files are sorted into categories
     by file type (.cpp, .h, .qrc, and so on). To display additional files, edit
-    the project file.
+    the project file. Alternatively, you can see all the files in a project
+    directory in the \l {File System} view.
 
-    Alternatively, you can see all the files in a project in the
-    \l {File System} view.
+    Declaring files as a part of the project also makes them visible to the
+    \l{Searching with the Locator}{locator} and \l{Advanced Search}
+    {project-wide search}.
 
     \section2 CMake Projects
 
-    When using CMake, you can specify additional files to display in the
-    \uicontrol Projects view by either adding them as sources or installing
-    them.
+    When using CMake, you can specify additional files for a project by either
+    adding them as sources or installing them.
 
     In the CMakeLists.txt file, define the files as values of the
     \l{CMake: target_sources command}{target_sources} command using
@@ -273,11 +285,17 @@
 
     \section2 qmake Projects
 
-    When using qmake, add filenames as values of the \c {DISTFILES} variable
-    in the .pro file. You can also use wildcards.
+    Use the following variables in the .pro file:
 
-    For example, the following value specifies that text files are part of the
-    project:
+    \list
+        \li \c SOURCES and \c HEADERS for files to compile
+        \li \c INSTALLS for files to install
+        \li \c DISTFILES for files to include in a source package
+        \li \c OTHER_FILES for files to manage with \QC without
+            installing them or including them in source packages
+    \endlist
+
+    For example, the following value includes text files in the source package:
 
     \badcode
 

doc/qtcreator/src/user-interface/creator-projects-view.qdoc

@@ -155,6 +155,9 @@
     allows to specify exactly where a new file should be placed in the build
     system.
 
+    If you cannot see some files, they might not be declared as part of the
+    project. For more information, see \l{Specifying Project Contents}.
+
     If the project is under version control, information from the version
     control system might be displayed in brackets after the project name.
     This is currently implemented for Git (the branch name or a tag is