update README.md with more detailed info about coverlet

Author: tonerdo

README.md

@@ -2,4 +2,74 @@
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-# coverlet
+# coverlet
+
+Coverlet is a cross platform code coverage library for .NET Core, with support for line and method coverage.
+
+## Installation
+
+Available on [NuGet](https://www.nuget.org/packages/coverlet.msbuild/)
+
+Visual Studio:
+
+```powershell
+PM> Install-Package coverlet.msbuild
+```
+
+.NET Core CLI:
+
+```bash
+dotnet add package coverlet.msbuild
+```
+
+## How It Works
+
+Coverlet integrates with the MSBuild system and that allows it to go through the following process:
+
+### Before Tests Run
+
+* Locate the unit test assembly and selects all the referenced assemblies that have PDBs.
+* Instruments the selected assemblies by inserting code to record sequence point hits to a temporary file.
+
+### After Tests Run
+
+* Restore the original non-instrumented assembly files.
+* Read the recorded hits information from the temporary file.
+* Generate the coverage result from the hits information and write it to a file.
+
+## Usage
+
+Coverlet deosn't require any additional setup other than including the NuGet package. It integrates with the `dotnet test` infrastructure built into the .NET Core CLI and when enabled will automatically generate coverage results after tests are run.
+
+### Code Coverage
+
+Enabling code coverage is as simple as setting the `CollectCoverage` property to `true`
+
+```bash
+dotnet test /p:CollectCoverage=true
+```
+
+After the above command is run, a `coverage.json` file containing the results will be generated in the root directory of the test project. A summary of the results will also be displayed in the terminal.
+
+### Coverage Output
+
+Coverlet can generate coverage results in multiple formats, which is specified using the `CoverletOutputFormat` property. Possible values include `json` (default), `lcov` and `opencover`. For example, the following command emits coverage results in the opencover format:
+
+```bash
+dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat=opencover
+```
+
+The output folder of the coverage result file can also be specified using the `CoverletOutputDirectory` property.
+
+## Roadmap
+
+* Branch coverage
+* Console runner (removes the need for requiring a NuGet package)
+
+## Issues & Contributions
+
+If you find a bug or have a feature request, please report them at this repository's issues section. Contributions are highly welcome, however, except for very small changes, kindly file an issue and let's have a discussion before you open a pull request.
+
+## License
+
+This project is licensed under the MIT license. See the [LICENSE](LICENSE) file for more info.