Update README to reflect multi-mission calibration

Author: heptaflar

README.md

@@ -19,7 +19,7 @@ objects rather than forcing the uncertainty calculus into a fixed set of
 closed‑form formulas.
 
 The concept presented here grew out of earlier project-specific implementations
-of AD-based uncertainty propagation for harmonized satellite calibration
+of AD-based uncertainty propagation for multi-mission sensor calibration
 workflows underpinning fundamental climate data records.
 
 ## Synopsis