Minor clarification

Because of the `cd DbConnector/` in the previous code section, it was unclear which location to run the `git submodule init` and `git submodule update` commands.

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

@@ -166,7 +166,7 @@ $
 ----
 
 The `DbConnector` directory is there, but empty.
-You must run two commands: `git submodule init` to initialize your local configuration file, and `git submodule update` to fetch all the data from that project and check out the appropriate commit listed in your superproject:
+You must run two commands from the main project: `git submodule init` to initialize your local configuration file, and `git submodule update` to fetch all the data from that project and check out the appropriate commit listed in your superproject:
 
 [source,console]
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