reorganization of the 'System Diagnostics/Debuggers' chapter

- signed-off-by: trimstray <trimstray@gmail.com>

README.md

@@ -132,10 +132,10 @@ for transferring data with URLs.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/draios/sysdig"><b>sysdig</b></a> - system exploration and troubleshooting tool with first class support for containers.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://nicolargo.github.io/glances/"><b>glances</b></a> - cross-platform system monitoring tool written in Python.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/hishamhm/htop"><b>htop</b></a> - interactive text-mode process viewer for Unix systems. It aims to be a better 'top'.<br>
+&nbsp;&nbsp;:small_orange_diamond: <a href="https://www.atoptool.nl/"><b>atop</b></a> - ASCII performance monitor. Includes statistics for CPU, memory, disk, swap, network, and processes.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://en.wikipedia.org/wiki/Lsof"><b>lsof</b></a> - displays in its output information about files that are opened by processes.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="http://www.brendangregg.com/flamegraphs.html"><b>FlameGraph</b></a> - stack trace visualizer.<br>
 &nbsp;&nbsp;:small_orange_diamond: <a href="https://github.com/zevv/lsofgraph"><b>lsofgraph</b></a> - small utility to convert Unix lsof output to a graph showing FIFO and UNIX interprocess communication.<br>
-&nbsp;&nbsp;:small_orange_diamond: <a href="https://www.atoptool.nl/"><b>atop</b></a> - ASCII performance monitor. Includes statistics for CPU, memory, disk, swap, network, and processes.<br>
 
 </p>