improved installation instructions

cpp/README

@@ -1,7 +1,38 @@
+TL;DR;
+-------
 run-once.sh runs your tests once
 
-Assumptions:
+Before this will work you will need:
   - make and a C++ compiler (like gcc) is installed on your system and is in the PATH
-  - The GTest framework is in the directory gtest.
+  - The GTest framework in the directory gtest.
   - If your IDE does the compilation and linking, you should remove the first 3 lines
     in the run-once.sh file.
+
+More Verbose Instructions
+-------------------------
+
+Create a clone of both GildedRose-Refactoring-Kata and googletest in a directory we'll call ${ROOT_INSTALL_DIR}:
+
+    cd ${ROOT_INSTALL_DIR}
+    git clone https://github.com/emilybache/GildedRose-Refactoring-Kata
+    git clone https://github.com/google/googletest
+
+Make googletest by running make in subfolder googletest/googletest/make:
+
+    cd googletest/googletest/make
+    make
+
+Create a softlink in the GildedRose-Refactoring-Kata clone pointing at the googletest code:
+
+    cd ${ROOT_INSTALL_DIR}/GildedRose-Refactoring-Kata/cpp
+    ln -s ${ROOT_INSTALL_DIR}/googletest/googletest gtest
+
+Make the GildedRose-Refactoring-Kata:
+
+    make
+
+Then you should be able to run the tests:
+
+    ./run_once.sh
+
+If you have been successful, then you should see a failing test, "GildedRoseTest.Foo".