fix Open Sourcerer description (#151)

Author: YasinDehfuli

README.md

@@ -217,7 +217,7 @@
 
 ## Open Sourcerer
 
-### the 'Open Sourcerer' achievement badges is is on test, After the official release. A step-by-step tutorial will be provided to receive it.
+### The 'Open Sourcerer' achievement badges are on test, After the official release. A step-by-step tutorial will be provided to receive it.
 
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