Added branching strategy etc. to docs (#191)

Added a section on the ideas behind the library and also explaining the
branching strategy.

---------

Co-authored-by: Dhanya Thattil <dhanya.thattil@psi.ch>

RELEASE.md

@@ -0,0 +1,22 @@
+# Release notes
+
+
+### head
+
+Features:
+
+- Cluster finder now works with 5x5, 7x7 and 9x9 clusters
+
+
+### 2025.05.22
+
+Features:
+
+- Added scurve fitting
+
+Bugfixes:
+
+- Fixed crash when opening raw files with large number of data files
+
+
+