Updated README

Author: gfraiteur

.gitignore

@@ -42,4 +42,5 @@ launchSettings.json
 .idea/workspace.xml
 /eng/tools
 *.Import.props
-*.g.props
+*.g.props
+*.log

README.md

@@ -2,4 +2,16 @@
 
 This repo is a template for new repos that are built using `PostSharp.Engineering`.
 
-For instructions, see https://github.com/postsharp/PostSharp.Engineering.
+This repo assumes it builds a product named `My.Product`. A _product_, in the context of PostSharp.Engineering, is essentially synonym to a repo, and it can produce several deployable artifacts, typically several NuGet packages. All artifacts in the same product have the same version and build number.
+
+After cloning the repo, you should do this:
+
+* Use `Build.ps1 tools git rename` to rename `My.Product` into your product name, _with_ dots.
+* Use Visual Studio Code find-and-replace all to rename:
+  * `My.Product` into your product name _with_ dots,
+  * `MyProduct` into your product name _without_ dots.
+
+The build entry point is `Build.ps1`.
+
+For more instructions, see https://github.com/postsharp/PostSharp.Engineering.
+