update history file

Author: TorkelE

HISTORY.md

@@ -16,6 +16,15 @@ assess_identifiability(goodwind_oscillator; measured_quantities=[:M])
 to assess (global) structural identifiability for all parameters and variables of the `goodwind_oscillator` model (under the presumption that we can measure `M` only).
 - Automatically handles conservation laws for structural identifiability problems (eliminates these internally to speed up computations).
 - Adds a tutorial to illustrate the use of the extension.
+- Enable adding metadata to individual reactions, e.g:
+```julia
+rn = @reaction_network begin
+    @parameters η
+    k, 2X --> X2, [noise_scaling=η]
+end
+get_metadata(rn, :noise_scaling)
+```
+- Changed fields of internal `Reaction` structure. `ReactionSystems`s saved using `serialize` on previous Catalyst versions cannot be loaded using this (or later) versions.
 - Simulation of spatial ODEs now supported. For full details, please see https://github.com/SciML/Catalyst.jl/pull/644 and upcoming documentation. Note that these methods are currently considered alpha, with the interface and approach changing even in non-breaking Catalyst releases.
 - LatticeReactionSystem structure represents a spatial reaction network:
   ```julia