docs: update badges in README and platform support info

Author: Brooooooklyn

README.md

@@ -2,5 +2,29 @@
 
 [![CircleCI](https://circleci.com/gh/LeetCode-OpenSource/py-sourcemap.svg?style=svg)](https://circleci.com/gh/LeetCode-OpenSource/py-sourcemap)
 [![Build Status](https://travis-ci.com/LeetCode-OpenSource/py-sourcemap.svg?branch=master)](https://travis-ci.com/LeetCode-OpenSource/py-sourcemap)
+[![Build status](https://ci.appveyor.com/api/projects/status/ubn6tpgyryapy319/branch/master?svg=true)](https://ci.appveyor.com/project/Brooooooklyn/py-sourcemap/branch/master)
+
 
 A tiny [source-map-mappings](https://github.com/fitzgen/source-map-mappings) bindings for python using [PyO3](https://github.com/PyO3/pyo3)
+
+# Platform Support
+
+### Operating Systems
+
+| Linux  | macOS | Windows x32 | Windows x64 |
+| ------ | ----- | ----------- | ----------- |
+| ✓      | ✓     | ✓           | ✓           |
+
+### Python
+
+| Python3.5 | Python3.6 | Python3.7 |
+| --------- | --------- | --------- |
+| ✓         | ✓         | ✓         |
+
+# Usage
+```python
+from py_sourcemap import SourcemapParser
+
+sourcemap_parser = SourcemapParser("./tests/index.js.map")
+sourcemap_parser.original_location_for(0, 195302) # (original_line, original_column, source_file_name, function_name_in_source)
+```