Readme update

README.txt

@@ -6,7 +6,7 @@
 
 This software is consisting of PDF rendering library, and viewer,
 which can display PDF documents. Software is implementing the PDF
-functionality based on PDF Reference 1.7. It is written and maintained
+functionality based on PDF Reference 2.0. It is written and maintained
 by Jakub Melka.
 
 1. ACKNOWLEDGEMENTS
@@ -24,10 +24,49 @@ file - LICENSE.txt to see details. This software also uses several
 third party software, and user of this software must also respect licenses
 of third party libraries.
 
-3. THIRD PARTY LIBRARIES
+3. FEATURES
 
-    a) libjpeg, see https://www.ijg.org/, version 9c.
+Software have following features (the list is not complete):
+
+ - multithreading support
+ - hardware accelerated rendering
+ - encryption
+ - color management
+ - optional content handling
+ - text layout analysis
+ - signature validation
+ - annotations
+ - form filling
+ - text to speech capability
+ - editation
+ - file attachments
+ - optimalization (compressing documents)
+ - much more!
+
+4. THIRD PARTY LIBRARIES
+
+    a) libjpeg, see https://www.ijg.org/
     b) FreeType, see https://www.freetype.org/index.html, FTL license used
     c) OpenJPEG, implementing Jpeg2000, see https://www.openjpeg.org/, 2-clause MIT license
     d) Qt, https://www.qt.io/, LGPL license used
     e) OpenSSL, https://www.openssl.org/, Apache 2.0 license
+    f) LittleCMS, http://www.littlecms.com/
+
+
+5. CONTRIBUTIONS
+
+If you want to contribute to this project, it is required, that you (contributor)
+transfer the copyright to me, because I want to have a freedom to do whatever
+I want with my library, without obligation to someone else. But I would strongly
+prefer, if you want to contribute, to contribute in the form of testing, consultation,
+giving advices etc. I would like to write this library entirely by myself.
+
+6. COMPILING
+
+To compile this project, Visual Studio 2019 is needed. Only Microsoft Windows
+is supported at this time. You must also have all of above libraries in order
+to compile the project.
+
+7. DISCLAIMER
+
+I wrote this project in my free time. I hope you will find it useful!