Tweak cheat sheet

CheatSheet.md

@@ -1,7 +1,16 @@
+# Form
+
 - One class per header file.
 - Place each data member on its own line.
 - Place each ctor-initializer on its own line.
 - Create typedefs for primitive types to describe them.
 - Return descriptive local variables instead of constants.
+- Use long descriptive names instead of abbreviations.
 - Use "explicit" for single-argument ctors
+- Avoid globals especially objects with static storage duration
 
+# Function
+
+- Minimize external dependencies
+  * Pass options in the ctor instead of using theConfig
+  * Use as few other classes as possible