feat: add overlap studies wrappers and align indicator API names

- add TA-Lib bindings and loader registrations for overlap studies:
  TA_ACCBANDS, TA_BBANDS, TA_DEMA, TA_EMA, TA_HT_TRENDLINE, TA_KAMA
- add new public wrappers in overlap_studies.go:
  AccBands, BBands, DEMA, EMA, HT_TRENDLINE, KAMA
- refactor momentum wrapper names to consistent Go-style exports
  (e.g. Aroon/AroonOsc, MACDExt/MACDFix, Stoch/StochF/StochRSI,
  MinusDI/MinusDM, PlusDI/PlusDM, Trix, UltOsc, WillR)
- rename MAType constants to MA_* for clearer namespacing
- update README to reflect the current exported API and overlap coverage

ta_ma_type.go

@@ -3,13 +3,13 @@ package talib
 type MAType int32
 
 const (
-	SMA   MAType = 0 // Simple Moving Average
-	EMA   MAType = 1 // Exponential Moving Average
-	WMA   MAType = 2 // Weighted Moving Average
-	DEMA  MAType = 3 // Double Exponential Moving Average
-	TEMA  MAType = 4 // Triple Exponential Moving Average
-	TRIMA MAType = 5 // Triangular Moving Average
-	KAMA  MAType = 6 // Kaufman Adaptive Moving Average
-	MAMA  MAType = 7 // MESA Adaptive Moving Average
-	T3    MAType = 8 // Triple Exponential Moving Average (T3)
+	MA_SMA   MAType = 0 // Simple Moving Average
+	MA_EMA   MAType = 1 // Exponential Moving Average
+	MA_WMA   MAType = 2 // Weighted Moving Average
+	MA_DEMA  MAType = 3 // Double Exponential Moving Average
+	MA_TEMA  MAType = 4 // Triple Exponential Moving Average
+	MA_TRIMA MAType = 5 // Triangular Moving Average
+	MA_KAMA  MAType = 6 // Kaufman Adaptive Moving Average
+	MA_MAMA  MAType = 7 // MESA Adaptive Moving Average
+	MA_T3    MAType = 8 // Triple Exponential Moving Average (T3)
 )