Docs - Update README for public view (#52)

* update README for public view

README.md

 # SuperBenchmark
 
-[![Build Status](https://dev.azure.com/msrasrg/SuperBenchmark/_apis/build/status/microsoft.superbenchmark?branchName=dev)](https://dev.azure.com/msrasrg/SuperBenchmark/_build?definitionId=77)
+[![Build Status](https://dev.azure.com/msrasrg/SuperBenchmark/_apis/build/status/cuda-unit-test?branchName=dev)](https://dev.azure.com/msrasrg/SuperBenchmark/_build/latest?definitionId=80&branchName=dev)
 [![Lint](https://github.com/microsoft/superbenchmark/workflows/Lint/badge.svg)](https://github.com/microsoft/superbenchmark/actions?query=workflow%3ALint)
 [![Codecov](https://codecov.io/gh/microsoft/superbenchmark/branch/dev/graph/badge.svg?token=DDiDLW7pSd)](https://codecov.io/gh/microsoft/superbenchmark/branch/dev)
 
@@ -21,46 +21,77 @@ which supports:
 It includes micro-benchmark for primitive computation and communication benchmarking,
 and model-benchmark to measure domain-aware end-to-end deep learning workloads.
 
+> 🔴 __Note__:
+SuperBench is in the early pre-alpha stage for open source, and not ready for general public yet.
+If you want to jump in early, you can try building [`dev` branch](https://github.com/microsoft/superbenchmark/tree/dev) yourself.
+
 
 ## Installation
 
+### Using Docker (_Preferred_)
+
+__System Requirements__
+
+* Platform: Ubuntu 18.04 or later (64-bit)
+* Docker: Docker CE 19.03 or later
+
+__Install SuperBench__
+
+* Using Pre-Build Images
+
+    ```sh
+    docker pull superbench/superbench:dev-cuda11.1.1
+    docker run -it --rm \
+        --privileged --net=host --ipc=host --gpus=all \
+        superbench/superbench:dev-cuda11.1.1 bash
+    ```
+
+* Building the Image
+
+    ```sh
+    docker build -f dockerfile/cuda11.1.1.dockerfile -t superbench/superbench:dev .
+    ```
+
 ### Using Python
 
-System requirements:
+__System Requirements__
+
+* Platform: Ubuntu 18.04 or later (64-bit); Windows 10 (64-bit) with WSL2
 * Python: Python 3.6 or later, pip 18.0 or later
-* Platform: Ubuntu 16.04 or later (64-bit), Windows 10 (64-bit) with WSL2
 
-Check whether Python environment is already configured:
-```sh
-# check Python version
-python3 --version
-# check pip version
-python3 -m pip --version
-```
-If not, install the followings:
-* [Python](https://www.python.org/)
-* [pip](https://pip.pypa.io/en/stable/installing/)
-* [venv](https://docs.python.org/3/library/venv.html)
+    Check whether Python environment is already configured:
+    ```sh
+    # check Python version
+    python3 --version
+    # check pip version
+    python3 -m pip --version
+    ```
+    If not, install the followings:
+    * [Python](https://www.python.org/)
+    * [pip](https://pip.pypa.io/en/stable/installing/)
+    * [venv](https://docs.python.org/3/library/venv.html)
 
-It's recommended to use a virtual environment (optional):
-```sh
-# create a new virtual environment
-python3 -m venv --system-site-packages ./venv
-# activate the virtual environment
-source ./venv/bin/activate
-
-# exit the virtual environment later
-# after you finish running superbench
-deactivate
-```
+    It's recommended to use a virtual environment (optional):
+    ```sh
+    # create a new virtual environment
+    python3 -m venv --system-site-packages ./venv
+    # activate the virtual environment
+    source ./venv/bin/activate
+
+    # exit the virtual environment later
+    # after you finish running superbench
+    deactivate
+    ```
 
-Then install superbench through either PyPI binary or from source:
+__Install SuperBench__
 
-1. PyPI Binary
+* PyPI Binary
 
-    TODO
+    ```sh
+    # not available yet
+    ```
 
-2. From Source
+* From Source
 
     ```sh
     # get source code
@@ -71,14 +102,22 @@ Then install superbench through either PyPI binary or from source:
     python3 -m pip install .
     ```
 
-### Using Docker
 
-TODO
+## Usage
 
+### Run SuperBench
 
-## Usage
+```sh
+# run benchmarks in default settings
+sb exec
+
+# use a custom config
+sb exec --config-file ./superbench/config/default.yaml
+```
+
+### Benchmark Gallary
 
-TODO
+Please find more benchmark examples [here](examples/benchmarks/).
 
 
 ## Developer Guide
@@ -146,16 +185,16 @@ SuperBenchmark is an open-source project. Your participation and contribution ar
 1. Bug fixes for existing features.
 2. New features for benchmark module (micro-benchmark, model-benchmark, etc.)
 
-   If you would like to contribute a new feature on SuperBenchmark, please submit your proposal first. In [GitHub Issues](https://github.com/microsoft/superbenchmark/issues) module, choose `Enhancement Request` to finish the submission. If the proposal is accepted, you can submit pull request to origin dev branch.
+   If you would like to contribute a new feature on SuperBenchmark, please submit your proposal first. In [GitHub Issues](https://github.com/microsoft/superbenchmark/issues) module, choose `Enhancement Request` to finish the submission. If the proposal is accepted, you can submit pull request to origin [`dev` branch](https://github.com/microsoft/superbenchmark/tree/dev).
 
 #### Contribution steps
 
 If you would like to contribute to the project, please follow below steps of joint development on GitHub.
 
 1. `Fork` the repo first to your personal GitHub account.
-2. Check out from `dev` branch for feature development.
+2. Check out from [`dev` branch](https://github.com/microsoft/superbenchmark/tree/dev) for feature development.
 3. When you finish the feature, please fetch the latest code from origin repo, merge to your branch and resolve conflict.
-4. Submit pull request to origin `dev` branch.
+4. Submit pull request to origin [`dev` branch](https://github.com/microsoft/superbenchmark/tree/dev).
 5. Please note that there might be comments or questions from reviewers. It will need your help to update the pull request.
 
 ## Trademarks