fixed bug in README

Author: ShSamariddin

README.md

@@ -2,7 +2,7 @@ String Search - Qt applications
 ====================================================
 Description
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-Created an analogue of GREP and directory indexing tools with UI for 
+Created a multi-threaded analogue of GREP and directory indexing tools with UI for 
 finding string occurences in the selected folder
 
 Install Qt 5 on Ubuntu