Updates with tested code and docs

Fixed typo
Updated document
Finished & tested LCs for:
- Delay
- Timer
- Delta
- Approx. Equal

src/main/programming/logic_condition.h

@@ -193,6 +193,7 @@ PG_DECLARE_ARRAY(logicCondition_t, MAX_LOGIC_CONDITIONS, logicConditions);
 
 typedef struct logicConditionState_s {
     int value;
+    int32_t lastValue;
     uint8_t flags;
     timeMs_t timeout;
 } logicConditionState_t;