fix typos (open-mmlab#670)

Author: Junjun2016

docs/get_started.md

@@ -49,10 +49,10 @@ Either `mmcv` or `mmcv-full` is compatible with MMSegmentation, but for methods
 
 **Install mmcv for Linux:**
 
-The pre-build mmcv-full (with PyTorch 1.5 and CUDA 10.1) can be installed by running: (other available versions could be found [here](https://mmcv.readthedocs.io/en/latest/#install-with-pip))
+The pre-build mmcv-full (with PyTorch 1.6 and CUDA 10.1) can be installed by running: (other available versions could be found [here](https://mmcv.readthedocs.io/en/latest/#install-with-pip))
 
 ```shell
-pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu101/torch1.5.0/index.html
+pip install mmcv-full -f https://download.openmmlab.com/mmcv/dist/cu101/torch1.6.0/index.html
 ```
 
 **Install mmcv for Windows (Experimental):**
@@ -124,7 +124,7 @@ conda create -n open-mmlab python=3.7 -y
 conda activate open-mmlab
 
 conda install pytorch=1.6.0 torchvision cudatoolkit=10.1 -c pytorch
-pip install mmcv-full==latest+torch1.5.0+cu101 -f https://download.openmmlab.com/mmcv/dist/index.html
+pip install mmcv-full==latest+torch1.6.0+cu101 -f https://download.openmmlab.com/mmcv/dist/index.html
 git clone https://github.com/open-mmlab/mmsegmentation.git
 cd mmsegmentation
 pip install -e .  # or "python setup.py develop"