Update readme with build, see #29 for details

Author: abelbraaksma

README.md

@@ -8,6 +8,45 @@ The `IAsyncEnumerable` interface was added to .NET in `.NET Core 3.0` and is par
 
 A good C#-based introduction on `IAsyncEnumerable` [can be found in this blog](https://stu.dev/iasyncenumerable-introduction/). Another resource is [this MSDN article shortly after its introductiono](https://learn.microsoft.com/en-us/archive/msdn-magazine/2019/november/csharp-iterating-with-async-enumerables-in-csharp-8).
 
+## Building & testing
+
+TLDR: just run `build`. Or load the `sln` file in Visual Studio or VS Code and compile.
+
+### Prerequisites
+
+* .NET 6 or .NET 7 Preview
+* F# 6.0 compiler
+* To use `build.cmd`, the `dotnet` command must be accessible from your path.
+
+Just checkout this repo. From the root of the repo:
+
+### Build the solution
+
+```
+build [release|debug]
+```
+
+### Run the tests
+
+```
+build test [release|debug]
+```
+
+### Run the CI command
+
+```
+build ci [release|debug]
+```
+
+### Get options
+
+```
+build help
+```
+
+For more info, see this PR: https://github.com/abelbraaksma/TaskSeq/pull/29.
+
+
 ## In progress!!!
 
 It's based on [Don Symes `taskSeq.fs`](https://github.com/dotnet/fsharp/blob/d5312aae8aad650f0043f055bb14c3aa8117e12e/tests/benchmarks/CompiledCodeBenchmarks/TaskPerf/TaskPerf/taskSeq.fs)