Add headline to installation details and move aside

website/docs/usage/index.jade

@@ -35,8 +35,9 @@ p
     +qs({model: 'de'}) python -m spacy download de
     +qs({model: 'fr'}) python -m spacy download fr
 
++h(2, "installation") Installation instructions
 
-+h(2, "pip") pip
++h(3, "pip") pip
     +badge("pipy")
 
 p Using pip, spaCy releases are currently only available as source packages.
@@ -44,6 +45,16 @@ p Using pip, spaCy releases are currently only available as source packages.
 +code(false, "bash").
     pip install -U spacy
 
++aside("Download models")
+    |  After installation you need to download a language model. For more info
+    |  and available models, see the #[+a("/docs/usage/models") docs on models].
+
+    +code.o-no-block.
+        python -m spacy download en
+
+        >>> import spacy
+        >>> nlp = spacy.load('en')
+
 p
     |  When using pip it is generally recommended to install packages in a
     |  #[code virtualenv] to avoid modifying system state:
@@ -53,7 +64,7 @@ p
     source .env/bin/activate
     pip install spacy
 
-+h(2, "conda") conda
++h(3, "conda") conda
     +badge("conda")
 
 p