DOC: update README

README.md

-General 
-=======
+# General
 
 This is a template module for the ORFEO
 Toolbox(https://www.orfeo-toolbox.org/). It is designed to work with OTBv5
@@ -9,52 +8,50 @@ This module is empty it is just a template to be used as a starting point for a
 module with actual content. It contains the template for sources (src folder),
 test (test folder) and application (app folder).
 
-Getting Started 
-===============
+# Getting Started
 
-The official OTB Wiki documentation on adding an external module is here:
-http://wiki.orfeo-toolbox.org/index.php/How_to_write_a_remote_module
+The official OTB Wiki documentation on adding an external module is
+[here](http://wiki.orfeo-toolbox.org/index.php/How_to_write_a_remote_module).
 
-Remote Module
--------------
+## Remote Module
 
 After a module has been created as a git repository it can be included
 as a remote module, which enables automatic fetching. Add a file in
 "OTB/Modules/Remote" called "YourModule.remote.cmake", for this module
 it would be "ExternalExample.remote.cmake" with the followlowing contents:
 
+```
 otb_fetch_module(ExternalTemplate
   "A template for a module."
   GIT_REPOSITORY https://github.com/orfeotoolbox/otbExternalModuleTemplate
   GIT_TAG master
   )
+```
 
-Editing
-======= 
+### Editing
 
 The CMakeLists.txt and otb-modules need to be modified with the name of the
 module, something along the following:
 
+```
 sed 's/ExternalTemplate/MyModule/g' CMakeLists.txt otb-module.cmake
+```
 
 There is the inplace option to sed, but it's not portable, so do this change by
 hand or look up the option in sed.
 
 Then hack away at you code in include, src, test and app folders.
 
-License 
-=======
+### License
 
 This software is distributed under the Apache License. Please see LICENSE for
 details.
 
-Author 
-======
+### Author
 
 Manuel Grizonnet
 
-Thanks 
-======
+### Thanks
 
 It is a fork of the ITK template module provided by Bradley Lowekamp
 (https://github.com/blowekamp/itkExternalTemplate.git) which was adapted for the