README: example: Update to oneTBB 2021.2.0

Author: hsbadr

README.md

@@ -24,7 +24,7 @@ To build the development version of `RcppParallel` with [`oneTBB`](https://githu
 For example, installing [`oneTBB`](https://github.com/oneapi-src/oneTBB) on Linux 64-bit (`x86_64`) to `$HOME` directory (change if needed!):
 
 ```bash
-TBB_VERSION="2021.1.1"
+TBB_VERSION="2021.2.0"
 
 wget https://github.com/oneapi-src/oneTBB/releases/download/v$TBB_VERSION/oneapi-tbb-$TBB_VERSION-lin.tgz
 tar zxvf oneapi-tbb-$TBB_VERSION-lin.tgz -C $HOME