clarify steps

Author: Don Syme

README.md

@@ -7,13 +7,13 @@ https://fsharp.github.io/fsharp-core-docs
 To improve the content of the F# Core library documentation, contribute to the XML `///` documentation in the
 signature files (`*.fsi`) in the FSharp.Core implementation.
 
-* Fork and clone https://github.com/dotnet/fsharp locally, see below
+* Fork and clone https://github.com/dotnet/fsharp locally, see below, as a subdirectory of your copy of `fsharp-core-docs`
 
 * Contribute to [the FSharp.Core directory ](https://github.com/dotnet/fsharp/tree/master/src/fsharp/FSharp.Core)
 
 * Use a local build, see below
 
-* Submit work to  `feature/docs` branch of https://github.com/dotnet/fsharp
+* Submit work to  `main` branch of https://github.com/dotnet/fsharp
 
 * Once accepted your work will be published through a rebuild here, so submit a dummy pull request here
 
@@ -23,7 +23,7 @@ The docs are generated by using `fsdocs` tool from FSharp.Formatting.  If you wa
 
 * Contribute to the API Docs mode and/or HTML generator in [FSharp.Formatting.ApiDocs](https://github.com/fsprojects/FSharp.Formatting/tree/master/src/FSharp.Formatting.ApiDocs) and [the `fsdocs` tool](https://github.com/fsprojects/FSharp.Formatting/tree/master/src/FSharp.Formatting.CommandTool) 
 
-* Use a local copy of these, see below
+* Use a local copy of these, see below, as a subdirectory of fsharp-core-docs
 
 * Submit work to the `master` branch of https://github.com/fsprojects/FSharp.Formatting