Well my original plan was that the default build instructions would be in a README.md file in the root of the source control as a verbatim block in the highest level heading containing the word "build"

If you needed any additional configuration for Jenkins specific instructions then that would be in a folder called ".jenkins"

Sadly, people did not embrace that project type... perhaps because it was given the nerdy name "literate" by a colleague of mine (who's name rhymes with Nichale Meale)