📝 Fix section levels

Author: mrkn

README.md

@@ -4,10 +4,10 @@ This is a Ruby kernel for Jupyter and is part of [SciRuby](http://sciruby.com/).
 
 ![Screenshot](https://cloud.githubusercontent.com/assets/50754/7956845/3fa46df8-09e3-11e5-8641-f5b8669061b5.png)
 
-### Quick start
+## Quick start
 The installation instructions are divided according to environments mainly because of ZeroMQ.
 
-#### Ubuntu 16.04
+### Ubuntu 16.04
 At first install Jupyter. I recommend an installation using [Anaconda](https://www.continuum.io/downloads) Python 3.6 version.
 
 After that, install the Ruby gem.
@@ -29,7 +29,7 @@ Now you can select Ruby kernel in Jupyter Notebook with:
 
     jupyter-notebook
 
-#### Windows
+### Windows
 At first install **git** and Jupyter. I recommend an installation using [Anaconda](https://www.continuum.io/downloads).
 
 Run the following commands on **Ruby command prompt**:
@@ -44,7 +44,7 @@ Now you can select Ruby kernel in Jupyter Notebook with:
 
     jupyter-notebook
 
-#### Mac
+### Mac
 I recommend an installation using [Anaconda](https://www.continuum.io/downloads).
 
 After that, run the following commands.
@@ -68,7 +68,7 @@ If you are using macports, run the following commands.
     gem install iruby
 
 
-#### FreeBSD
+### FreeBSD
 
 At first install IPython/Jupyter. 
 There is a pyzmq ports (ports/net/py-pyzmq) which depends on libzmq4, however, it doesn't works with ipython.
@@ -106,7 +106,7 @@ Then, install iruby and related ports and gems.
     $ gem build iruby.gemspec
     $ sudo gem install iruby-0.2.7.gem
     ```
-### Installation for jRuby
+## Installation for jRuby
 
 Since jRuby is fully compatible with Ruby version 2.2, it is possible to use iruby with jRuby. 
 It can be helpful if you want to use java classes in your iruby notebook.
@@ -126,14 +126,14 @@ $ iruby register --force
 ```
 After that you can use iruby with jRuby in usual way.
 
-### After the installation
+## After the installation
 
 Take a look at the [example notebook](http://nbviewer.ipython.org/urls/raw.github.com/SciRuby/sciruby-notebooks/master/getting_started.ipynb)
 and the [collection of notebooks](https://github.com/SciRuby/sciruby-notebooks/) which includes a Dockerfile to create a containerized installation of iruby
 and other scientific gems. You can find the prebuild image at [dockerhub](https://registry.hub.docker.com/u/minad/sciruby-notebooks/).
 
 
-### Required dependencies
+## Required dependencies
 
 * Jupyter >= 3.0.0
 * Ruby >= 2.1.0
@@ -142,11 +142,11 @@ If you install IRuby with CZTop, CZMQ >= 4.0.0 is added to the list above.
 
 If you install IRuby with ffi-rzmq, libzmq >= 3.2 is added to the list above.
 
-### Authors
+## Authors
 
 See the [CONTRIBUTORS](CONTRIBUTORS) file.
 
-### License
+## License
 
 Copyright © 2013-15, IRuby contributors and the Ruby Science Foundation.