add requirements.txt at install django section

en/django_installation/instructions.md

@@ -167,7 +167,12 @@ Before we do that, we should make sure we have the latest version of `pip`, the
 (myvenv) ~$ python3 -m pip install --upgrade pip
 ```
 
-Then run `pip install django~=2.0.6` to install Django.
+### Installing packages with requirements
+
+A requirements file keep a list of dependencies to be installed using
+`pip install`:
+
+First, run `pip install django~=2.0.6` to install Django.
 
 {% filename %}command-line{% endfilename %}
 ```
@@ -204,4 +209,15 @@ data-collapse=true ces-->
 
 <!--endsec-->
 
+Let's create a `requirements.txt`, run `pip freeze > requirements.txt` to save `django~=2.0.6` as a dependency of the project.
+
+The `requirements.txt` should be inside of `blog/`:
+
+```
+blog
+└───requirements.txt
+```
+
+
+
 That's it! You're now (finally) ready to create a Django application!

en/extend_your_application/README.md

@@ -66,7 +66,7 @@ urlpatterns = [
 ]
 ```
 
-This part ``post/<int:pk>/`` specify a url pattern – we will explain it for you:
+This part ``post/<int:pk>/`` specifies a URL pattern – we will explain it for you:
 - `post/` just means that the URL should begin with the word __post__ followed by a __/__. So far so good.
 - `<int:pk>` – this part is trickier. It means that Django expects an integer value and will transfer it to a view as a variable called `pk`.
 - `/` – then we need a __/__ again before finishing the url.