qbs: add QbsProfile doc (#3825)

Author: ABBAPOH

reference/tools/qbs.rst

@@ -8,3 +8,4 @@ conan.tools.qbs
 
    qbs/qbs
    qbs/qbsdeps
+   qbs/qbsprofile

reference/tools/qbs/qbs.rst

@@ -12,7 +12,7 @@ commands automatically when a package is being built directly by Conan (create,
 .. code-block:: python
 
     from conan import ConanFile
-    from conan.tools.qbs import Qbs, QbsDeps
+    from conan.tools.qbs import Qbs, QbsProfile, QbsDeps
 
     class App(ConanFile):
         settings = "os", "arch", "compiler", "build_type"
@@ -22,6 +22,8 @@ commands automatically when a package is being built directly by Conan (create,
         default_options = {"shared": False, "fPIC": True}
 
         def generate(self):
+            profile = QbsProfile(self)
+            profile.generate()
             deps = QbsDeps(self)
             deps.generate()
 

reference/tools/qbs/qbsprofile.rst

@@ -0,0 +1,63 @@
+.. _conan_tools_qbsprofile:
+
+QbsProfile
+===========
+
+The ``QbsProfile`` generator produces the settings file that contains toolchain information.
+This file can be imported into Qbs. The ``QbsProfile`` generator can be used like:
+
+.. code-block:: python
+
+    from conan import ConanFile
+
+    class App(ConanFile):
+        settings = "os", "arch", "compiler", "build_type"
+        requires = "hello/0.1"
+        generators = "QbsProfile"
+
+
+It is also possible to use ``QbsProfile`` manually in the ``generate()`` method:
+
+.. code-block:: python
+
+    from conan import ConanFile
+    from conan.tools.qbs import QbsProfile
+
+    class App(ConanFile):
+        settings = "os", "arch", "compiler", "build_type"
+        requires = "hello/0.1"
+
+        def generate(self):
+            profile = QbsProfile(self)
+            profile.generate()
+
+Now we can generate the file using the ``conan install`` command.
+
+.. code-block:: text
+
+    $ conan install . --output-folder=build --build missing
+
+And import it into Qbs:
+
+.. code-block:: text
+
+    $ qbs config import qbs_settings.txt --settings-dir qbs
+
+Note that to acutually use the imported file, Qbs should be called with ``--settings-dir``:
+
+.. code-block:: text
+
+    $ qbs resolve --settings-dir qbs
+
+Those commands are called automatically when using the ``Qbs`` helper class.
+.. seealso::
+
+    - Check the :ref:`Qbs helper <_conan_tools_qbs_helper>` for details.
+
+Reference
+---------
+
+.. currentmodule:: conan.tools.qbs.qbsprofile
+
+.. autoclass:: QbsProfile
+    :members: