docs: Add component manager documentation

docs/en/api-guides/tools/idf-component-manager.rst

@@ -0,0 +1,72 @@
+*********************
+IDF Component Manager
+*********************
+
+The IDF Component manager is a tool that downloads dependencies for any ESP-IDF CMake project. The download happens automatically during a run of CMake. It can source components either from `the component registry <https://components.espressif.com>`_ or from a git repository.
+
+A list of components can be found on `<https://components.espressif.com/>`_
+
+Activating the Component Manager
+================================
+
+If CMake is started using ``idf.py`` or `ESP-IDF VSCode Extension <https://marketplace.visualstudio.com/items?itemName=espressif.esp-idf-extension>`_ then the component manager will be activated by default.
+
+If CMake is used directly or with some CMake-based IDE like CLion, it's necessary to set the ``IDF_COMPONENT_MANAGER`` environment variable to ``1`` to enable the component manager integration with the build system.
+
+Using with a project
+====================
+
+Dependencies for each component in the project are defined in a separate manifest file named ``idf_component.yml`` placed in the root of the component. The manifest file template can be created for a component by running ``idf.py create-manifest --component=my_component``. When a new manifest is added to one of the components in the project it's necessary to reconfigure it manually by running ``idf.py reconfigure``. Then build will track changes in ``idf_component.yml`` manifests and automatically triggers CMake when necessary.
+
+There is an example application: example:`build_system/cmake/component_manager` that uses components installed by the component manager.
+
+It's not necessary to have a manifest for components that don't need any managed dependencies.
+
+When CMake configures the project (e.g. ``idf.py reconfigure``) component manager does a few things:
+
+- Processes ``idf_component.yml`` manifests for every component in the project and recursively solves dependencies
+- Creates a ``dependencies.lock`` file in the root of the project with a full list of dependencies
+- Downloads all dependencies to the ``managed_components`` directory
+
+The lock-file ``dependencies.lock`` and content of ``managed_components`` directory is not supposed to be modified by a user. When the component manager runs it always make sure they are up to date. If these files were accidentally modified it's possible to re-run the component manager by triggering CMake with ``idf.py reconfigure``
+
+Defining dependencies in the manifest
+=====================================
+
+.. code-block:: yaml
+
+    dependencies:
+      # Required IDF version
+      idf: ">=4.1"
+      # Defining a dependency from the registry:
+      # https://components.espressif.com/component/example/cmp
+      example/cmp: ">=1.0.0"
+
+      # # Other ways to define dependencies
+      #
+      # # For components maintained by Espressif only name can be used.
+      # # Same as `espressif/cmp`
+      # component: "~1.0.0"
+      #
+      # # Or in a longer form with extra parameters
+      # component2:
+      #   version: ">=2.0.0"
+      #
+      #   # For transient dependencies `public` flag can be set.
+      #   # `public` flag doesn't affect the `main` component.
+      #   # All dependencies of `main` are public by default.
+      #   public: true
+      #
+      #   # For components hosted on non-default registry:
+      #   service_url: "https://componentregistry.company.com"
+      #
+      # # For components in git repository:
+      # test_component:
+      #   path: test_component
+      #   git: ssh://git@gitlab.com/user/components.git
+      #
+      # # For test projects during component development
+      # # components can be used from a local directory
+      # # with relative or absolute path
+      # some_local_component:
+      #   path: ../../projects/component

docs/en/api-guides/tools/index.rst

@@ -7,3 +7,4 @@ Tools
    IDF Tools <idf-tools>
    IDF Monitor <idf-monitor>
    IDF Docker image <idf-docker-image>
+   IDF Component Manager <idf-component-manager>

docs/zh_CN/api-guides/tools/idf-component-manager.rst

@@ -0,0 +1 @@
+.. include:: ../../../en/api-guides/tools/idf-component-manager.rst

docs/zh_CN/api-guides/tools/index.rst

@@ -7,3 +7,4 @@
    IDF Tools <idf-tools>
    IDF 监视器 <idf-monitor>
    IDF Docker image <idf-docker-image>
+   IDF Component Manager <idf-component-manager>