Update README.md

(Try to) Fix the readme problems found by the feedmereadmes guys:

* Tuned up the tagline
* Added info about what for, history, competitors, etc.
* Put more links for potential contributors

README.md

 <p align="center"><img src="https://criu.org/w/images/1/1c/CRIU.svg" width="256px"/></p>
 
-## CRIU (Checkpoint and Restore in Userspace)
+## CRIU -- A project to implement checkpoint/restore functionality for Linux
 
-An utility to checkpoint/restore tasks. Using this tool, you can freeze a
-running application (or part of it) and checkpoint it to a hard drive as a
-collection of files. You can then use the files to restore and run the
-application from the point it was frozen at. The distinctive feature of the CRIU
-project is that it is mainly implemented in user space.
+CRIU (stands for Checkpoint and Restore in Userspace) is an utility to checkpoint/restore Linux tasks.
 
-Also, CRIU provides a library for Live migration, and exposes two low-level
-core features as standalone libraries. Thes are libcompel for parasite code 
-injection and libsoccr for TCP connections checkpoint-restore.
+Using this tool, you can freeze a running application (or part of it) and checkpoint 
+it to a hard drive as a collection of files. You can then use the files to restore and run the
+application from the point it was frozen at. The distinctive feature of the CRIU
+project is that it is mainly implemented in user space. There are some more projects
+doing C/R for Linux, and so far CRIU [appears to be](https://criu.org/Comparison_to_other_CR_projects) 
+the most feature-reach and up-to-date with the kernel.
 
-The project home is at http://criu.org.
+The project [started](https://criu.org/History) as the way to do live migration for OpenVZ
+Linux containers, but later grew to more sophisticated and flexible tool. It is currently 
+used by (integrated into) OpenVZ, LXC/LXD, Docker, and other software, project gets tremendous 
+help from the community, and its packages are included into many Linux distributions.
 
+The project home is at http://criu.org. This wiki contains all the knowledge base for CRIU we have.
 Pages worth starting with are:
-- [Kernel configuration, compilation, etc](http://criu.org/Installation)
+- [Installation instructions](http://criu.org/Installation)
 - [A simple example of usage](http://criu.org/Simple_loop)
-- [More sophisticated example with graphical app](http://criu.org/VNC)
+- [Examples of more advanced usage](https://criu.org/Category:HOWTO)
+- Troubleshooting can be hard, some help can be found [here](https://criu.org/When_C/R_fails), [here](https://criu.org/What_cannot_be_checkpointed) and [here](https://criu.org/FAQ)
 
 ### A video tour on basic CRIU features
 [![CRIU introduction](https://asciinema.org/a/7fnt2prsumvxiwf3ng61fgct3.png)](https://asciinema.org/a/7fnt2prsumvxiwf3ng61fgct3)
 
-## Live migration
+## Advanced features
+
+As main usage for CRIU is live migration, there's a library for it called P.Haul. Also the
+project exposes two cool core features as standalone libraries. These are libcompel for parasite code 
+injection and libsoccr for TCP connections checkpoint-restore.
+
+### Live migration
 
 True [live migration](https://criu.org/Live_migration) using CRIU is possible, but doing
 all the steps by hands might be complicated. The [phaul sub-project](https://criu.org/P.Haul)
 provides a Go library that incapsulates most of the complexity.
 
-## Parasite code ijection
+### Parasite code ijection
 
 In order to get state of the running process CRIU needs to make this process execute
 some code, that would fetch the required information. To make this happen without
 killing the application itself, CRIU uses the [parasite code injection](https://criu.org/Parasite_code)
 technique, which is also available as a standalone library called [libcompel](https://criu.org/Compel).
 
-## TCP sockets checkpoint-restore
+### TCP sockets checkpoint-restore
 
 One of the CRIu features is the ability to save and restore state of a TCP socket
 without breaking the connection. This functionality is considered to be useful by
@@ -43,10 +53,18 @@ tiself, and we have it available as the [libsoccr library](https://criu.org/Libs
 
 ## How to contribute
 
-* [How to submit patches](http://criu.org/How_to_submit_patches);
-* Send all bug reports to [mailing
-list](https://lists.openvz.org/mailman/listinfo/criu);
+CRIU project is (almost) the never ending story, because we have to always keep-up with the
+Linux kernel supporting checkpoint and restore for all the features it provides. Thus we're
+looking for contributors of all kinds -- feedback, bug reports, testing, coding, writing, etc.
+Here are some useful hints to get involved.
+
+* We have both -- [very simple](https://github.com/xemul/criu/issues?q=is%3Aissue+is%3Aopen+label%3Aenhancement) and [more sophisticated](https://github.com/xemul/criu/issues?q=is%3Aissue+is%3Aopen+label%3A%22new+feature%22) coding tasks;
+* CRIU does need [extensive testing](https://github.com/xemul/criu/issues?q=is%3Aissue+is%3Aopen+label%3Atesting);
+* Documentation is always hard, we have [some information](https://criu.org/Category:Empty_articles) that is to be extracted from people's heads into wiki pages as well as [some texts](https://criu.org/Category:Editor_help_needed) that all need to be converted into useful articles;
+* Feedback is expected on the github issues page and on the [mailing list](https://lists.openvz.org/mailman/listinfo/criu);
+* For historical reasons we do not accept PRs, instead [patches are welcome](http://criu.org/How_to_submit_patches);
 * Spread the word about CRIU in [social networks](http://criu.org/Contacts);
+* If you're giving a talk about CRIU -- let us know, we'll mention it on the [wiki main page](https://criu.org/News/events);
 
 ## Licence