Merge pull request #11 from stephanlachnit/limdor-patch-1

Update paper.md

Author: stephanlachnit

paper.md

@@ -17,6 +17,19 @@ toc: true
 
 This paper proposes element access with bounds checking to `std::mdspan` via `at()` member functions.
 
+# Revision history
+
+## R1
+
+Update wording to align with [@P2821R5]:
+
+- Bump `__cpp_lib_mdspan` instead of adding `__cpp_lib_mdspan_at`
+- Mark `at()` as freestanding deleted and adjust freestanding comments of header and class
+
+## R0
+
+Initial version
+
 # Motivation
 
 ## Safety