Update user documentation

docs/source/release/v5.1.0/muon.rst

@@ -9,5 +9,16 @@ MuSR Changes
     putting new features at the top of the section, followed by
     improvements, followed by bug fixes.
 
+Muon Analysis 2
+################
+
+New Features
+------------
+- The plotting logic within the Muon Analysis 2 GUI has updated to prevent all the workspaces from a
+  fit being plotted at the same time. Instead, the choice of which fit workspace to plot can be made in
+  fitting and sequential fitting tabs.
+- When the user switches to the fitting tab, the workspace present in the fit display box is plotted.
+  To switch back to a view of all the data, the user can switch to the home, grouping or phase table tabs.
+- The sequential fitting table now allows multiple selections to be made.
 
 :ref:`Release 5.1.0 <v5.1.0>`
\ No newline at end of file