Added sup performance graphs/document to 'docs'.

Details:
- Added a new markdown document, docs/PerformanceSmall.md, which
  publishes new performance graphs for Kaby Lake and Epyc showcasing
  the new BLIS sup (small/skinny/unpacked) framework logic and kernels.
  For now, only single-threaded dgemm performance is shown.
- Reorganized graphs in docs/graphs into docs/graphs/large, with new
  graphs being placed in docs/graphs/sup.
- Updates to scripts in test/sup/octave, mostly to allow decent output
  in both GNU octave and Matlab.
- Updated README.md to mention and refer to the new PerformanceSmall.md
  document.

test/sup/octave/runme.m

@@ -1,4 +1,8 @@
 
-% has
-plot_panel_trxsh(3.5,16,1,'st','d','ccc',[ 6 8 4 ],'../results','has','MKL'); close; clear all;
-plot_panel_trxsh(3.5,16,1,'st','d','rrr',[ 6 8 4 ],'../results7','has','MKL'); close; clear all;
+% kabylake
+plot_panel_trxsh(3.6,16,1,'st','d','rrr',[ 6 8 4 ],'../results/kabylake/20190531/4_800_4_mt201_last400','kbl','MKL','matlab'); close; clear all;
+plot_panel_trxsh(3.6,16,1,'st','d','ccc',[ 6 8 4 ],'../results/kabylake/20190531/4_800_4_mt201_last400','kbl','MKL','matlab'); close; clear all;
+
+% epyc
+plot_panel_trxsh(3.0,8,1,'st','d','rrr',[ 6 8 4 ],'../results/epyc/20190531/4_800_4_mt256_last400','epyc','MKL','matlab'); close; clear all;
+plot_panel_trxsh(3.0,8,1,'st','d','ccc',[ 6 8 4 ],'../results/epyc/20190531/4_800_4_mt256_last400','epyc','MKL','matlab'); close; clear all;