README updates

Author: Reptarsrage

README.md

@@ -68,6 +68,7 @@ Options:
   --include          Filter expressions to include specific modules and types.
   --exclude-by-file  Glob patterns specifying source files to exclude.
   --merge-with       Path to existing coverage result to merge.
+  --teamcity-output  Output coverage results to console using TeamCity service messages.
 ```
 
 #### Code Coverage
@@ -194,6 +195,27 @@ Examples
 
 Both `--exclude` and `--include` options can be used together but `--exclude` takes precedence. You can specify the `--exclude` and `--include` options multiple times to allow for multiple filter expressions.
 
+#### TeamCity Output
+
+Coverlet can output basic code coverage statistics using [TeamCity service messages](https://confluence.jetbrains.com/display/TCD18/Build+Script+Interaction+with+TeamCity#BuildScriptInteractionwithTeamCity-ServiceMessages).
+
+```bash
+coverlet <ASSEMBLY> --target <TARGET> --targetargs <TARGETARGS> --teamcity-output
+```
+
+The currently supported [TeamCity statistics](https://confluence.jetbrains.com/display/TCD18/Build+Script+Interaction+with+TeamCity#BuildScriptInteractionwithTeamCity-ServiceMessages) are:
+| TeamCity Statistic Key  | Description                    |
+| :---                    | :---                           |
+| CodeCoverageL           | Line-level code coverage       |
+| CodeCoverageC           | Class-level code coverage      |
+| CodeCoverageM           | Method-level code coverage     |
+| CodeCoverageAbsLTotal   | The total number of lines      |
+| CodeCoverageAbsLCovered | The number of covered lines    |
+| CodeCoverageAbsCTotal   | The total number of classes    |
+| CodeCoverageAbsCCovered | The number of covered classes  |
+| CodeCoverageAbsMTotal   | The total number of methods    |
+| CodeCoverageAbsMCovered | The number of covered methods  |
+
 ### MSBuild
 
 In this mode, Coverlet doesn't require any additional setup other than including the NuGet package in the unit test project. 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.
@@ -275,6 +297,27 @@ dotnet test /p:CollectCoverage=true /p:Threshold=80 /p:ThresholdType=line
 
 You can specify multiple values for `ThresholdType` by separating them with commas. Valid values include `line`, `branch` and `method`.
 
+#### TeamCity Output
+
+Coverlet can output basic code coverage statistics using [TeamCity service messages](https://confluence.jetbrains.com/display/TCD18/Build+Script+Interaction+with+TeamCity#BuildScriptInteractionwithTeamCity-ServiceMessages).
+
+```bash
+dotnet test /p:CollectCoverage=true /p:TeamCityOutput=true
+```
+
+The currently supported [TeamCity statistics](https://confluence.jetbrains.com/display/TCD18/Build+Script+Interaction+with+TeamCity#BuildScriptInteractionwithTeamCity-ServiceMessages) are:
+| TeamCity Statistic Key  | Description                    |
+| :---                    | :---                           |
+| CodeCoverageL           | Line-level code coverage       |
+| CodeCoverageC           | Class-level code coverage      |
+| CodeCoverageM           | Method-level code coverage     |
+| CodeCoverageAbsLTotal   | The total number of lines      |
+| CodeCoverageAbsLCovered | The number of covered lines    |
+| CodeCoverageAbsCTotal   | The total number of classes    |
+| CodeCoverageAbsCCovered | The number of covered classes  |
+| CodeCoverageAbsMTotal   | The total number of methods    |
+| CodeCoverageAbsMCovered | The number of covered methods  |
+
 #### Excluding From Coverage
 
 ##### Attributes