add sed script for frac_auth changes

CHANGELOG.md

@@ -143,7 +143,8 @@ Changes in Coq:
 * Add the camera `ufrac` for unbounded fractions (i.e. without fractions that
   can be `> 1`) and the camera `ufrac_auth` for a variant of the authoritative
   fractional camera (`frac_auth`) with unbounded fractions.
-* Changed `frac_auth` notation from `●!`/`◯!` to `●F`/`◯F`.
+* Changed `frac_auth` notation from `●!`/`◯!` to `●F`/`◯F`. sed script:
+  `s/◯!/◯F/g; s/●!/●F/g;`.
 
 ## Iris 3.1.0 (released 2017-12-19)