Update CHANGELOG for version 2.7.5: add notes on guidata dependency update and new translation utility

Author: PierreRaybaut

CHANGELOG.md

@@ -6,6 +6,11 @@
 
 * [Issue #44](https://github.com/PlotPyStack/PlotPy/issues/44) - Incorrect calculation method for "∑(y)" in `CurveStatsTool`: replaced `spt.trapezoid` with `np.sum`, which is more consistent with the summation operation
 
+Other changes:
+
+* Updated `guidata` dependency to V3.10.0
+* Using new `guidata` translation utility based on `babel`
+
 ## Version 2.7.4 ##
 
 In this release, test coverage is 80%.