Update docs/src/catalyst_applications/advanced_simulations.md

Co-authored-by: Sam Isaacson <[email protected]>

Author: TorkelE

docs/src/catalyst_applications/advanced_simulations.md

@@ -309,7 +309,7 @@ sprob_1 = SDEProblem(rn_1, u0, tspan, p_1)
 sol_1 = solve(sprob_1)
 plot(sol_1; idxs = :X1, ylimit = (0.0, 20.0))
 ```
-Here we can see that the `X` concentration fluctuations around a steady state of $X≈10.0$.
+Here we can see that the `X` concentration fluctuates around a steady state of $X≈10.0$.
 
 Next, we wish to introduce a noise scaling parameter ,`η`. This will scale the
 noise magnitude so that for $η≈0.0$ the system lacks noise (and its SDE