Fix typo in README.rst (#3880)

Fix typo in NuGet package manager reference in README.rst
By https://github.com/Crown0815

Author: Crown0815

README.rst

@@ -89,7 +89,7 @@ Why use ScanCode?
   InstallShield installers, iOS apps, ISO images, Apache IVY, JBoss Sar,
   R CRAN, Apache Maven, Meteor, Mozilla extensions, MSI installers,
   JavaScript npm packages, package-lock.json, yarn.lock, NSIS Installers,
-  NugGet, OPam, Cocoapods, Python PyPI setup.py, setup.cfg, and 
+  NuGet, OPam, Cocoapods, Python PyPI setup.py, setup.cfg, and 
   several related lockfile formats, semi structured README
   files such as README.android, README.chromium, README.facebook, README.google,
   README.thirdparty, RPMs, Shell Archives, Squashfs images, Java WAR, Windows