doc: add pretty output doc

Author: RafaelGSS

README.md

@@ -14,3 +14,60 @@ packages operations.
 - [x] pinojs
 - [x] winston
 - [x] underscore
+
+## Running
+
+To a pretty terminal output, run `index.js`
+
+```console
+$ node index.js
+Running Node.js Package Benchmark...
+----------------------------------------------------------
+babel
+  transform (code=true ast=true):                         70.09 (3 samples)
+  transform (code=false):                                 78.57 (2 samples)
+dotenv
+  config:                                                 31.09K (5 samples)
+lodash
+  .chunk:                                                 24.47M (5 samples)
+  .groupBy:                                               3.343M (7 samples)
+  .includes:                                              10.35M (6 samples)
+  .orderBy:                                               921.3K (8 samples)
+moment
+  format (full):                                          504.7K (7 samples)
+  format:                                                 441K (4 samples)
+  fromNow (YYYYMMDD):                                     73K (9 samples)
+  subtract (10):                                          134K (5 samples)
+pinojs
+  info (10x):                                             109.1K (4 samples)
+prettier
+  format (semi=true):                                     773.5K (3 samples)
+  format (singleQuote=true semi=true tabs=true):          593.7K (3 samples)
+  format (singleQuote=false semi=false tabs=false):       473.4K (3 samples)
+underscore
+  .chunk:                                                 3.15M (3 samples)
+  .groupBy:                                               1.003M (3 samples)
+  .includes:                                              6.588M (4 samples)
+  .orderBy:                                               488.7K (5 samples)
+winston
+  info (10x):                                             24.48K (4 samples)
+```
+
+To store it as JSON, just pipe output to a file:
+
+```console
+$ node index.js > results.json
+$ cat result.json
+[
+  {
+    "name": "babel",
+    "method": "benchmarkjs",
+    "operations": [
+      {
+        "name": "transform (code=true ast=true)",
+        "opsSec": 67.80076532539411,
+        "samples": 3
+      },
+      {
+...
+```