Fixed few grammer mistakes in source.md

Fixed few grammer mistakes in source.md

Author: mohantym

site/en/install/source.md

@@ -78,7 +78,7 @@ Use [Git](https://git-scm.com/){:.external} to clone the
 <code class="devsite-terminal">cd tensorflow</code>
 </pre>
 
-The repo defaults to the `master` development branch. You can also checkout a
+The repo defaults to the `master` development branch. You can also check out a
 [release branch](https://github.com/tensorflow/tensorflow/releases){:.external}
 to build:
 
@@ -141,7 +141,7 @@ Found cuDNN 7 in:
 
 
 Please specify a list of comma-separated CUDA compute capabilities you want to build with.
-You can find the compute capability of your device at: https://developer.nvidia.com/cuda-gpus. Each capability can be specified as "x.y" or "compute_xy" to include both virtual and binary GPU code, or as "sm_xy" to only include the binary code.
+You can find compute capability of your device at: https://developer.nvidia.com/cuda-gpus. Each capability can be specified as "x.y" or "compute_xy" to include both virtual and binary GPU code, or as "sm_xy" to only include the binary code.
 Please note that each additional compute capability significantly increases your build time and binary size, and that TensorFlow only supports compute capabilities >= 3.5 [Default is: 3.5,7.0]: 6.1