Add RefactoringDiary to document my refactoring journey

csharpcore/GildedRose/RefactoringDiary.md

@@ -0,0 +1,18 @@
+This file documents my refactoring and design journey while working through in this kata.
+
+NOTES:
+- At this stage, I assume that when we're not supposed to change Item or Items, we shouldn't just ignore them and create a parallel object types to use (that include the different DailyUpdate behaviours).
+- This code and requirements were simple enough that I could have created the final version, or at least a massive refactoring immediately.
+  However, I wanted to experience and demonstrate the refactoring process by small steps that can be just as easily applied to more complex code.
+
+
+## My refactoring steps:
+1. Added full test coverage drawing from the requirements and the existing 30 days texttest test.<br>
+Some of the tests failed due to bugs I discovered in the code/existing tests (e.g. relying on exact name instead of the mentioned "code word"). 
+I decorated these tests with `[Ignore]` until I get to a stage in the refactoring where I can easily fix the issues and re-introduce the tests.   
+2. small refactorings of the UpdateQuality() method to make it more readable and separate the different (unrelated) handling of the different types.<br>
+
+This is the state of the code now
+
+
+