docs/quickstart: Tweak Introduction section

Drop the first second level heading as superfluous. Note that the
listing of supported protocols is not actually exhaustive. In the
feature listing, group single thread and non-blocking I/O together.
Fix the name of SystemTap.

Signed-off-by: Jussi Virtanen <jussi.k.virtanen@gmail.com>

docs/quickstart.md

@@ -1,17 +1,14 @@
 # Introduction
 
-## What **libtrading** is
-
 **Libtrading** is an open source API that implements network protocols used for
-communicating with exchanges, dark pools, and other trading venues. For the list
-of all supported protocols one may refer to the **Supported Protocols** section.
+communicating with exchanges, dark pools, and other trading venues. For a list
+of supported protocols, see the *Supported Protocols* section.
 
 ## Features
 
-* No memory allocation in RX and TX paths
-* Single-threaded philosophy
-* System Tap/DTrace probes
-* Non-blocking IO support
+* No memory allocation on the RX and TX paths
+* Single-threaded, non-blocking I/O philosophy
+* SystemTap/DTrace probes
 
 # Supported Protocols