README: add missing adapters and flash drivers, mention profiling

This updates README with all the "keywords" added since the initial
upstream submission (and finally fixes the typo in the beginning).

Change-Id: Ia071267246fe6afc19fc0bfcda83c4778e7ff5b1
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/1624


Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>