Add CONTRIBUTING.md

Author: liammclennan

CONTRIBUTING.md

@@ -0,0 +1,57 @@
+Contributing to seqcli
+================
+
+Testing
+------
+
+`seqcli` has two test projects: `SeqCli.EndToEnd` and `SeqCli.Tests`.
+
+### SeqCli.EndToEnd 
+
+`/test/SeqCli.EndToEnd` is a console app that implements integration tests. It uses a custom testing framework and xunit for assertions. 
+
+Each test within the EndToEnd project (an implementation of the `ICliTestCase` interface) spans one child process for the Seq server and one child process for the seqcli command. 
+
+The Seq server can be run via the `seq` executable (windows only) or as a `datalust/seq:latest` docker container. Which to use is controlled via the `--docker-server` argument. 
+
+Some tests require a Seq license. These tests are run if a valid license is supplied via stdin and the `--license-certificate-stdin` argument is supplied. 
+
+#### Adding Tests
+
+The typical pattern is to execute a seqcli command, then make an assertion on the output of the command. E.g.
+
+```c#
+var exit = runner.Exec("apikey list", "-t Test --json --no-color");
+Assert.Equal(0, exit);
+
+var output = runner.LastRunProcess!.Output;
+Assert.Contains("\"AssignedPermissions\": [\"Ingest\"]", output);
+```
+
+#### Running Tests
+
+```shell
+/SeqCli.EndToEnd$ dotnet run -- --docker-server
+```
+
+The `--docker-server` is optional if you have a `seq` executable in your path.
+
+To run the multi user tests as well, save a valid license into a file and:
+
+```shell
+/SeqCli.EndToEnd$ cat license.txt | dotnet run -- --docker-server --license-certificate-stdin
+```
+
+To run a specific set of tests pass regular expressions matching the tests to run:
+
+```shell
+/SeqCli.EndToEnd$ dotnet run -- --docker-server *TestCase.cs Command*
+```
+
+### SeqCli.Tests
+
+`/test/SeqCli.Tests` is a regular xunit testing project. To run: 
+
+```shell
+/SeqCli.Tests$ dotnet test
+```

README.md

@@ -50,6 +50,10 @@ $token = (
 )
 ```
 
+## Contributing
+
+See `CONTRIBUTING.md`.
+
 ## Commands
 
 Usage:

seqcli.sln

@@ -17,6 +17,7 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "sln", "sln", "{2EA56595-519
 		Build.Docker.ps1 = Build.Docker.ps1
 		docker-publish.ps1 = docker-publish.ps1
 		Setup.ps1 = Setup.ps1
+		CONTRIBUTING.md = CONTRIBUTING.md
 	EndProjectSection
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{3587B633-0C03-4235-8903-6226900328F1}"