Replace the obscure term 'vendoring' with 'copying'

Author: crd

book/07-git-tools/sections/submodules.asc

@@ -10,7 +10,7 @@ Suppose you’re developing a web site and creating Atom feeds.
 Instead of writing your own Atom-generating code, you decide to use a library.
 You’re likely to have to either include this code from a shared library like a CPAN install or Ruby gem, or copy the source code into your own project tree.
 The issue with including the library is that it’s difficult to customize the library in any way and often more difficult to deploy it, because you need to make sure every client has that library available.
-The issue with vendoring the code into your own project is that any custom changes you make are difficult to merge when upstream changes become available.
+The issue with copying the code into your own project is that any custom changes you make are difficult to merge when upstream changes become available.
 
 Git addresses this issue using submodules.
 Submodules allow you to keep a Git repository as a subdirectory of another Git repository.