Add coverage and metrics badges to README

Added coverage and metrics badges to README.

Author: marcin-golebiowski

README.md

@@ -2,6 +2,9 @@
 
 [![NuGet](https://img.shields.io/nuget/v/SpiceSharp-Parser.svg)](https://www.nuget.org/packages/SpiceSharp-Parser)
 [![License: MIT](https://img.shields.io/badge/License-MIT-yellow.svg)](LICENSE)
+[![Coverage](https://sonarcloud.io/api/project_badges/measure?project=SpiceSharp_SpiceSharpParser&metric=coverage)](https://sonarcloud.io/summary/new_code?id=SpiceSharp_SpiceSharpParser)
+[![Lines of Code](https://sonarcloud.io/api/project_badges/measure?project=SpiceSharp_SpiceSharpParser&metric=ncloc)](https://sonarcloud.io/summary/new_code?id=SpiceSharp_SpiceSharpParser)
+[![Duplicated Lines (%)](https://sonarcloud.io/api/project_badges/measure?project=SpiceSharp_SpiceSharpParser&metric=duplicated_lines_density)](https://sonarcloud.io/summary/new_code?id=SpiceSharp_SpiceSharpParser)
 
 A .NET library that parses SPICE netlists and simulates them using [SpiceSharp](https://github.com/SpiceSharp/SpiceSharp). It supports a wide subset of PSpice and LTspice syntax including DC, AC, transient, noise, and operating-point analyses.