Update readme (#1107)

* State that wifi collector is disabled by default

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

* Add the 'processes' collector to the Readme

Signed-off-by: Bryan Boreham <bjboreham@gmail.com>

README.md

@@ -53,7 +53,6 @@ time | Exposes the current system time. | _any_
 timex | Exposes selected adjtimex(2) system call stats. | Linux
 uname | Exposes system information as provided by the uname system call. | Linux
 vmstat | Exposes statistics from `/proc/vmstat`. | Linux
-wifi | Exposes WiFi device and station statistics. | Linux
 xfs | Exposes XFS runtime statistics. | Linux (kernel 4.4+)
 zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics. | [Linux](http://zfsonlinux.org/)
 
@@ -70,11 +69,13 @@ logind | Exposes session counts from [logind](http://www.freedesktop.org/wiki/So
 meminfo\_numa | Exposes memory statistics from `/proc/meminfo_numa`. | Linux
 mountstats | Exposes filesystem statistics from `/proc/self/mountstats`. Exposes detailed NFS client statistics. | Linux
 ntp | Exposes local NTP daemon health to check [time](./docs/TIME.md) | _any_
+processes | Exposes aggregate process statistics from `/proc`. | Linux
 qdisc | Exposes [queuing discipline](https://en.wikipedia.org/wiki/Network_scheduler#Linux_kernel) statistics | Linux
 runit | Exposes service status from [runit](http://smarden.org/runit/). | _any_
 supervisord | Exposes service status from [supervisord](http://supervisord.org/). | _any_
 systemd | Exposes service and system status from [systemd](http://www.freedesktop.org/wiki/Software/systemd/). | Linux
 tcpstat | Exposes TCP connection status information from `/proc/net/tcp` and `/proc/net/tcp6`. (Warning: the current version has potential performance issues in high load situations.) | Linux
+wifi | Exposes WiFi device and station statistics. | Linux
 
 ### Textfile Collector