doc: Add an example for sorting abbreviated numeric values

Author: tenF

README.md

@@ -547,6 +547,17 @@ Nicolaus Bernoulli
 keep-sorted end
 ```
 
+```
+// keep-sorted start numeric=yes
+Data Size A 20M
+Data Size A 50K
+Data Size A 250M
+Data Size B 1B
+Data Size B 80M
+Data Size B 250K
+// keep-sorted end
+```
+
 </td>
 <td>
 
@@ -596,6 +607,17 @@ keep-sorted end
  keep-sorted end
 ```
 
+```diff
++// keep-sorted start numeric=yes by_regex=(?i)(.*?)(?:(\d+)b|(\d+)m|(\d+)k)
+Data Size A 50K
+Data Size A 20M
+Data Size A 250M
+Data Size B 250K
+Data Size B 80M
+Data Size B 1B
+// keep-sorted end
+```
+
 </td>
 </tr>
 </table>