Update Conda description in PyTorch README (#20726)

Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/20726

Edward says it doesn't actually provide compilers,
but it does provide dependencies, so let's mention that instead.

Reviewed By: ezyang

Differential Revision: D15423316

fbshipit-source-id: 9b384f88e5bf7a3d2c132508620c276b49e1569f
diff --git a/README.md b/README.md
index 3b4ee37..ea94c82 100644
--- a/README.md
+++ b/README.md
@@ -151,7 +151,7 @@
 ### From Source
 
 If you are installing from source, we highly recommend installing an [Anaconda](https://www.anaconda.com/distribution/#download-section) environment.
-You will get a high-quality BLAS library (MKL) and you get a controlled compiler version regardless of your Linux distro.
+You will get a high-quality BLAS library (MKL) and you get controlled dependency versions regardless of your Linux distro.
 
 Once you have [Anaconda](https://www.anaconda.com/distribution/#download-section) installed, here are the instructions.
 
@@ -183,7 +183,7 @@
 git clone --recursive https://github.com/pytorch/pytorch
 cd pytorch
 # if you are updating an existing checkout
-git submodule sync 
+git submodule sync
 git submodule update --init --recursive
 ```