Fix precommit hook for docs/installation.rst (apache#10759)

* Fix precommit hook for docs/installation.rst

* Fix underline too short

docs/installation.rst

@@ -55,34 +55,34 @@ are stateless, so you can scale out by running on as many servers
 as needed.
 
 Install and Deploy Superset Locally with Docker
------------------
+-----------------------------------------------
 
 To try Superset locally, the
 best-supported currently method is via Docker, using ``docker-compose``. Superset
 does not have official support for Windows, so we have provided a VM
 workaround below. (We will update this documentation once Windows is
 supported.)
 
-**Step 0 - Install a Docker Engine and Docker Compose** 
+**Step 0 - Install a Docker Engine and Docker Compose**
 
 *Mac OSX:*
-        
+
     `Install Docker for Mac <https://docs.docker.com/docker-for-mac/install/>`__, which includes the Docker engine and a recent version of `docker-compose` out of the box.
-    
+
     Once you have Docker for Mac installed, open up the preferences pane for Docker, go to the "Resources" section and increase the allocated memory to 6GB. With only the 2GB of RAM allocated by default, Superset will fail to start.
 
 
 *Linux:*
 
     `Install Docker on Linux <https://docs.docker.com/engine/install/>`__ by following Docker’s instructions for whichever flavor of Linux suits you.
-    
+
     Because ``docker-compose`` is not installed as part of the base Docker installation on Linux, once you have a working engine, follow the `docker-compose installation instructions <https://docs.docker.com/compose/install/>`__ for Linux.
 
 
 *Windows:*
 
     NOTE: Windows is currently not a supported environment for Superset installation.
-    
+
     For Windows users, the best option may be to install an Ubuntu Desktop VM via `VirtualBox <https://www.virtualbox.org/>`__ and proceed with the Docker on Linux instructions inside of that VM. It is recommended to assign at least 8GB of RAM to the virtual machine as well as provisioning a hard drive of at least 40GB, so that there will be enough space for both the OS and all of the required dependencies.
 
 **Step 1 - Clone Superset's Github repository**
@@ -104,13 +104,13 @@ Next, `cd` into the folder you created in Step 1:
 .. code:: bash
 
     $ cd incubator-superset
-    
+
 Once you're in the directory, run the following command:
 
 .. code:: bash
 
     $ docker-compose up
-    
+
 You should see a wall of logging output from the containers being
 launched on your machine. Once this output slows to a crawl, you should
 have a running instance of Superset on your local machine!
@@ -129,7 +129,7 @@ Log in with the default username and password:
 ::
 
     username: admin
-    password: admin 
+    password: admin
 
 Congrats! You have successfully installed Superset!