[squashme] Add note about git checkout for Windows development

doc/build-windows.md

@@ -72,6 +72,16 @@ the permissions of all extracted files with command like:
 
   sudo chmod -R <your_username> .
 
+If you've downloaded via `git`, do not use `sudo`. Instead prefer something like:
+
+    cd $HOME
+    git clone https://github.com/dogecoin/dogecoin.git
+    git checkout <branchname>
+
+... where `<branchname>` is the name of the branch you want to build, such as
+"1.14.7-dev" for the unstable branch or "master" for the most recent stable
+release.
+
 ## Building for 64-bit Windows
 
 To build executables for Windows 64-bit, install the following dependencies: