Added alternative multi-threading (#82)

Co-authored-by: Arif Rahmadi <41944717+arifrahmd@users.noreply.github.com>

Author: arfrhmd

README.md

@@ -1262,6 +1262,20 @@ bash -v scriptname
 bash -x scriptname
 ```
 
+# 5. Multi-threading
+You can easily multi-threading your jobs using `&`. All those jobs will then run in the background simultaneously and you can see the processes below are running using `jobs`.
+
+```bash
+sleep 15 & sleep 5 &
+```
+
+The optional `wait` command will then wait for all the jobs to finish.
+
+```bash
+sleep 10 & sleep 5 &
+wait
+```
+
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