Fix note block syntax in docs

docs/2_installation.rst

@@ -83,7 +83,7 @@ Axes has the following warnings codes built in:
 - ``axes.W003`` for invalid ``AUTHENTICATION_BACKENDS`` configuration.
 
 
-.. note:
+.. note::
    Only disable the Axes system checks and warnings if you know what you are doing.
    The default checks are implemented to verify and improve your project's security
    and should only produce necessary warnings due to misconfigured settings.

docs/3_usage.rst

@@ -100,7 +100,7 @@ In your code, you can use the ``axes.utils.reset`` function.
 - ``reset(ip=ip)`` will clear lockouts and records for the given IP address.
 - ``reset(username=username)`` will clear lockouts and records for the given username.
 
-.. note:
+.. note::
    Please note that if you give both ``username`` and ``ip`` arguments to ``reset``
    that attempts that have both the set IP and username are reset.
    The effective behaviour of ``reset`` is to ``and`` the terms instead of ``or`` ing them.

docs/5_customization.rst

@@ -149,7 +149,7 @@ into ``my_namespace-username``:
 
     AXES_USERNAME_CALLABLE = 'example.utils.get_username'
 
-.. note:
+.. note::
    You still have to make these modifications yourself before calling
    authenticate. If you want to re-use the same function for consistency, that's
    fine, but Axes does not inject these changes into the authentication flow