Update README.md

sorry, I'm not a native speaker, missing an 'if'

Author: YaoHuiJi

README.md

@@ -53,7 +53,7 @@ import { MainBundlePath, DocumentDirectoryPath } from 'react-native-fs'
 
 ***NOTE: only support zip folder, not file entries***
 
-***NOTE: the string version of source is for folder, the string[] version is for file, so you want to zip a single file, use zip([file]) instead of zip(file)***
+***NOTE: the string version of source is for folder, the string[] version is for file, so if you want to zip a single file, use zip([file]) instead of zip(file)***
 
 Example
 
@@ -76,7 +76,7 @@ zip(sourcePath, targetPath)
 
 ***NOTE: only support zip folder, not file entries***
 
-***NOTE: the string version of source is for folder, the string[] version is for file, so you want to zip a single file, use zip([file]) instead of zip(file)***
+***NOTE: the string version of source is for folder, the string[] version is for file, so if you want to zip a single file, use zip([file]) instead of zip(file)***
 
 ***NOTE: encryptionType is not supported on iOS yet, so it would be igonred on that platform.***