Fix flask tutorial (#269)

* Fix highlight

* Fix flask tutorial rst issues

* Fix some wording

docs/tutorials/flask.rst

@@ -75,22 +75,30 @@ Initial project layout::
 
 Now it's time to install ``Flask`` and ``Dependency Injector``.
 
-Put next lines into the ``requirements.txt`` file::
+Put next lines into the ``requirements.txt`` file:
+
+.. code-block:: bash
 
    dependency-injector
    flask
 
-Now let's install it::
+Now let's install it:
+
+.. code-block:: bash
 
    pip install -r requirements.txt
 
-And check that installation is successful::
+And check that installation is successful:
+
+.. code-block:: bash
 
    python -c "import dependency_injector; print(dependency_injector.__version__)"
    python -c "import flask; print(flask.__version__)"
 
 
-You should see something like::
+You should see something like:
+
+.. code-block:: bash
 
    (venv) $ python -c "import dependency_injector; print(dependency_injector.__version__)"
    3.22.0
@@ -116,7 +124,7 @@ Put next into the ``views.py``:
 
 Ok, we have the view.
 
-Now let's create the heart of our application - the container. Container will keep all of the
+Now let's create the main part of our application - the container. Container will keep all of the
 application components and their dependencies. First two providers we need to add are
 the ``Flask`` application provider and the view provider.
 
@@ -142,8 +150,8 @@ Put next into the ``containers.py``:
 
 Finally we need to create the Flask application factory. It is traditionally called
 ``create_app()``. It will create the container. Then it will use the container to create
-the Flask application. Last step is to configure the routing - we will assign ``index_view`` from the
-container to handle user requests to the root ``/`` if our web application.
+the Flask application. Last step is to configure the routing - we will assign ``index_view`` from
+the container to handle user requests to the root ``/`` of our web application.
 
 Put next into the ``application.py``:
 
@@ -173,13 +181,17 @@ Put next into the ``application.py``:
 
 Ok. Now we're ready to say "Hello, World!".
 
-Do next in the terminal::
+Do next in the terminal:
+
+.. code-block:: bash
 
    export FLASK_APP=githubnavigator.application
    export FLASK_ENV=development
    flask run
 
-The output should be something like::
+The output should be something like:
+
+.. code-block:: bash
 
     * Serving Flask app "githubnavigator.application" (lazy loading)
     * Environment: development
@@ -205,14 +217,16 @@ It will help us to add all needed static files in few clicks.
 
 Add ``bootstrap-flask`` to the ``requirements.txt``:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 3
 
    dependency-injector
    flask
    bootstrap-flask
 
-and run in the terminal::
+and run in the terminal:
+
+.. code-block:: bash
 
    pip install --upgrade -r requirements.txt
 
@@ -276,7 +290,7 @@ the ``githubnavigator`` package. We also will need two files there:
 
 Create ``templates`` folder and put two empty files into it ``base.html`` and ``index.html``:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 3-5
 
    ./
@@ -442,7 +456,7 @@ We will use `PyGithub <https://github.com/PyGithub/PyGithub>`_ library for worki
 
 Let's add it to the ``requirements.txt``:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 4
 
    dependency-injector
@@ -450,7 +464,9 @@ Let's add it to the ``requirements.txt``:
    bootstrap-flask
    pygithub
 
-and run in the terminal::
+and run in the terminal:
+
+.. code-block:: bash
 
    pip install --upgrade -r requirements.txt
 
@@ -509,7 +525,7 @@ We will use YAML.
 
 Create an empty file ``config.yml`` in the root root of the project:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 11
 
    ./
@@ -525,7 +541,9 @@ Create an empty file ``config.yml`` in the root root of the project:
    ├── config.yml
    └── requirements.txt
 
-and put next into it::
+and put next into it:
+
+.. code-block:: yaml
 
    github:
      request_timeout: 10
@@ -535,7 +553,7 @@ file. Let's add it to the requirements file.
 
 Edit ``requirements.txt``:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 5
 
    dependency-injector
@@ -544,7 +562,9 @@ Edit ``requirements.txt``:
    pygithub
    pyyaml
 
-and install it::
+and install it:
+
+.. code-block:: bash
 
    pip install --upgrade -r requirements.txt
 
@@ -617,7 +637,7 @@ Now it's time to add ``SearchService``. It will:
 
 Create empty file ``services.py`` in the ``githubnavigator`` package:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 9
 
    ./
@@ -758,7 +778,7 @@ Now let's inject the ``SearchService`` dependency into the ``index`` view.
 Edit ``containers.py``:
 
 .. code-block:: python
-   :emphasize-lines: 32-38
+   :emphasize-lines: 32-35
 
    """Application containers module."""
 
@@ -890,7 +910,7 @@ Finally let's update the config.
 
 Edit ``config.yml``:
 
-.. code-block::
+.. code-block:: yaml
    :emphasize-lines: 3-5
 
    github:
@@ -913,7 +933,7 @@ We will use `pytest <https://docs.pytest.org/en/stable/>`_ and
 
 Edit ``requirements.txt``:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 6-7
 
    dependency-injector
@@ -924,14 +944,15 @@ Edit ``requirements.txt``:
    pytest-flask
    pytest-cov
 
-And let's install it::
+And let's install it:
+
+.. code-block:: bash
 
    pip install -r requirements.txt
 
-
 Create empty file ``tests.py`` in the ``githubnavigator`` package:
 
-.. code-block::
+.. code-block:: bash
    :emphasize-lines: 10
 
    ./
@@ -1024,13 +1045,15 @@ and put next into it:
        assert response.status_code == 200
        assert b'Results found: 0' in response.data
 
-Now let's run it and check the coverage::
+Now let's run it and check the coverage:
+
+.. code-block:: bash
 
    py.test githubnavigator/tests.py --cov=githubnavigator
 
 You should see:
 
-.. code-block::
+.. code-block:: bash
 
    platform darwin -- Python 3.8.3, pytest-5.4.3, py-1.9.0, pluggy-0.13.1
    plugins: flask-1.0.0, cov-2.10.0
@@ -1064,8 +1087,8 @@ We are done.
 It this tutorial we've build ``Flask`` application following dependency injection principle.
 We've used ``Dependency Injector`` as a dependency injection framework.
 
-The heart of this application is the container. It keeps all the application components and their
-dependencies in one place:
+The main part of this application is the container. It keeps all the application components and
+their dependencies in one place:
 
 .. code-block:: python