improve README

Author: vchuravy

README.md

@@ -1,5 +1,53 @@
 # ParallelTestRunner.jl
 
+Simple parallel test runner for Julia tests with autodiscovery.
+
+## Usage
+
+```julia
+julia> import Pkg
+
+julia> Pkg.test("ParallelTestRunner"; test_args=["--help"])
+
+Usage: runtests.jl [--help] [--list] [--jobs=N] [TESTS...]
+
+   --help             Show this text.
+   --list             List all available tests.
+   --verbose          Print more information during testing.
+   --quickfail        Fail the entire run as soon as a single test errored.
+   --jobs=N           Launch `N` processes to perform tests (default: Sys.CPU_THREADS).
+
+   Remaining arguments filter the tests that will be executed.
+```
+
+## Setup
+
+`ParallelTestRunner` runs each file inside your `test/` concurrently and isolated.
+First you should remove all `include` statements that you added.
+
+Then in your `test/runtests.jl` add:
+
+```julia
+using ParallelTestRunner
+
+runtests(ARGS)
+```
+
+### Filtering
+
+`runtests` takes a second argument that acts as a filter function
+
+```julia
+function testfilter(test)
+    if Sys.iswindows() && test == "ext/specialfunctions"
+        return false
+    end
+    return true
+end
+
+runtests(ARGS, testfilter)
+```
+
 
 ## Inspiration
-Based on @maleadt test infrastructure for CUDA.jl and Julia Base.
+Based on [@maleadt](https://github.com/maleadt) test infrastructure for [CUDA.jl](https://github.com/JuliaGPU/CUDA.jl).

test/runtests.jl

@@ -1,4 +1,3 @@
-using Test
 using ParallelTestRunner
 
-runtests(ARGS)
+runtests(ARGS)