Improve a bit the readme

README.md

@@ -12,6 +12,21 @@
 This software is currently in **beta**, please don't use it for anything
 critical.
 
+# Metadata and privacy
+
+Metadata consist of information that characterizes data.                                             
+Metadata are used to provide documentation for data products.                                        
+In essence, metadata answer who, what, when, where, why, and how about                               
+every facet of the data that are being documented.                                                   
+
+Metadata within a file can tell a lot about you.                                                     
+Cameras record data about when a picture was taken and what                                          
+camera was used. Office documents like PDF or Office automatically adds                              
+author and company information to documents and spreadsheets.                                        
+Maybe you don't want to disclose those information on the web. 
+
+This is precisely the job of MAT2: getting rid, as much as possible, of
+metadata.
 
 # Requirements
 
@@ -29,6 +44,12 @@ doesn't run on [Debian Jessie](Stretc://packages.debian.org/jessie/python3),
 $ python3 -m unittest discover -v
 ```
 
+# Supported formats
+
+```bash
+$ python3 ./main.py -l
+```
+
 # Related softwares
 
 - The first iteration of [MAT](http://mat.boum.org)
@@ -37,3 +58,31 @@ $ python3 -m unittest discover -v
 	tries to deal with *printer dots* too.
 - [pdfparanoia](https://github.com/kanzure/pdfparanoia), that removes
 	watermarks from PDF.
+
+# License
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Copyright 2018 Julien (jvoisin) Voisin <julien.voisin+mat2@dustri.org>
+
+# Thanks
+
+MAT2 wouldn't existe without:
+
+- the Google Summer of Code,
+- the fine people from the Tails project
+- friends
+
+Many thanks to them!
+