Drop Support section in README and reorganize its content (#2301)

1. Remove link to Google discussion group since the latter does not seem to be active/maintained.
2. Remove link to FAQ since it is present just below on the Wiki section.
3. Move tweet and recommend options in the User testimonial section where they fit better.
4. Add an explicit call for action sentence to clearly indicate the purpose of the links.

Author: zabetak

README.md

@@ -126,6 +126,9 @@ Open source software like HikariCP, like any product, competes in the free marke
 [![](https://github.com/brettwooldridge/HikariCP/wiki/tweet2.png)](https://twitter.com/brettemeyer)<br/>
 [![](https://github.com/brettwooldridge/HikariCP/wiki/tweet4.png)](https://twitter.com/dgomesbr/status/527521925401419776)
 
+If you like this project, consider leaving a word for us on social media:
+
+[![](https://raw.github.com/wiki/brettwooldridge/HikariCP/twitter.png)](https://twitter.com/share?text=Interesting%20JDBC%20Connection%20Pool&hashtags=HikariCP&url=https%3A%2F%2Fgithub.com%2Fbrettwooldridge%2FHikariCP)&nbsp;[![](https://raw.github.com/wiki/brettwooldridge/HikariCP/facebook.png)](http://www.facebook.com/plugins/like.php?href=https%3A%2F%2Fgithub.com%2Fbrettwooldridge%2FHikariCP&width&layout=standard&action=recommend&show_faces=true&share=false&height=80)
 ------------------------------
 ### :gear: Configuration (knobs, baby!)
 HikariCP comes with *sane* defaults that perform well in most deployments without additional tweaking. **Every property is optional, except for the "essentials" marked below.**
@@ -545,12 +548,6 @@ A new JRuby wrapper has been created by [tomekw](https://github.com/tomekw) and
 
 ----------------------------------------------------
 
-### Support <sup><sup>&#128172;</sup></sup>
-
-Google discussion group [HikariCP here](https://groups.google.com/d/forum/hikari-cp), growing [FAQ](https://github.com/brettwooldridge/HikariCP/wiki/FAQ).
-
-[![](https://raw.github.com/wiki/brettwooldridge/HikariCP/twitter.png)](https://twitter.com/share?text=Interesting%20JDBC%20Connection%20Pool&hashtags=HikariCP&url=https%3A%2F%2Fgithub.com%2Fbrettwooldridge%2FHikariCP)&nbsp;[![](https://raw.github.com/wiki/brettwooldridge/HikariCP/facebook.png)](http://www.facebook.com/plugins/like.php?href=https%3A%2F%2Fgithub.com%2Fbrettwooldridge%2FHikariCP&width&layout=standard&action=recommend&show_faces=true&share=false&height=80)
-
 ### Wiki
 
 Don't forget the [Wiki](https://github.com/brettwooldridge/HikariCP/wiki) for additional information such as: