Update Installation page

Hint about asyncio

docs/source/start/Installation.rst

@@ -14,17 +14,17 @@ by following the instructions at https://pip.pypa.io/en/latest/installing/.
 Install Pyrogram
 ----------------
 
--   The easiest way to install and upgrade Pyrogram is by using **pip**:
+-   The easiest way to install and upgrade Pyrogram to its latest stable version is by using **pip**:
 
-    .. code-block:: bash
+    .. code-block:: text
 
         $ pip3 install --upgrade pyrogram
 
--   or, with TgCrypto_ (recommended):
+-   or, with TgCrypto_ as extra requirement (recommended):
 
-    .. code-block:: bash
+    .. code-block:: text
 
-        $ pip3 install --upgrade pyrogram[tgcrypto]
+        $ pip3 install --upgrade pyrogram[fast]
 
 Bleeding Edge
 -------------
@@ -32,21 +32,53 @@ Bleeding Edge
 If you want the latest development version of Pyrogram, you can install it straight from the develop_
 branch using this command (you might need to install **git** first):
 
-.. code-block:: bash
+.. code-block:: text
 
     $ pip3 install --upgrade git+https://github.com/pyrogram/pyrogram.git
 
+Asynchronous
+------------
+
+Pyrogram heavily depends on IO-bound network code (it's a cloud-based messaging client library after all), and here's
+where asyncio shines the most by providing extra performance while running on a single OS-level thread only.
+
+**A fully asynchronous variant of Pyrogram is therefore available** (Python 3.5+ required).
+Use this command to install:
+
+.. code-block:: text
+
+    $ pip3 install --upgrade git+https://github.com/pyrogram/pyrogram.git@asyncio
+
+
+Pyrogram API remains the same and features are kept up to date from the non-async, default develop branch.
+
+
+.. note::
+
+    The idea to turn Pyrogram fully asynchronous is still under consideration, but is wise to expect that in future this
+    would be the one and only way to work with Pyrogram.
+
+.. raw:: html
+
+    <script async
+        src="https://telegram.org/js/telegram-widget.js?4"
+        data-telegram-post="Pyrogram/4"
+        data-width="100%">
+    </script>
+
+.. centered:: Subscribe to `@Pyrogram <https://t.me/Pyrogram>`_ for news and announcements
+
 Verifying
 ---------
 
 To verify that Pyrogram is correctly installed, open a Python shell and import it.
 If no error shows up you are good to go.
 
-.. code-block:: bash
+.. code-block:: python
 
     >>> import pyrogram
     >>> pyrogram.__version__
     '0.8.0'
 
 .. _TgCrypto: https://docs.pyrogram.ml/resources/TgCrypto
-.. _develop: http://github.com/pyrogram/pyrogram
+.. _develop: http://github.com/pyrogram/pyrogram