Update index.md

writing fix

Author: TorkelE

docs/src/index.md

@@ -47,7 +47,7 @@ etc).
   ODE/SDE/jump solver, and can be used within `EnsembleProblem`s for carrying
   out parallelized parameter sweeps and statistical sampling. Plot recipes
   are available for visualizing the solutions.
-- [Symbolics.jl](https://github.com/JuliaSymbolics/Symbolics.jl)) symbolic
+- [Symbolics.jl](https://github.com/JuliaSymbolics/Symbolics.jl) symbolic
   expressions and Julia `Expr`s can be obtained for all rate laws and functions
   determining the deterministic and stochastic terms within resulting ODE, SDE
   or jump models.