Update README.md

Author: ATPs

README.md

@@ -122,6 +122,11 @@ vcf2mutation --help
 ```
 from the console directly. 
 
+Note:
+
+* the contents in folder `examples` and `test_output` were not included in the installation package.
+* If you want to test the with the examples or check more running examples and results, use `git clone https://github.com/ATPs/PrecisionProDB.git` or download from the link https://github.com/ATPs/PrecisionProDB/archive/refs/heads/master.zip directly.
+
 ## run test files