solver choice docs upd

Author: ivborissov

docs/src/basics/solvers.md

@@ -10,11 +10,21 @@ One can also set relative and absolute tolerances (`reltol`, `abstol`) and other
 
 If no solver is provided the default one `AutoTsit5(Rosenbrock23())` will be used with `reltol=1e-3` and `abstol=1e-6` for simulation problems and `reltol=1e-6` and `abstol=1e-8` for parameters estimation.
 
+```julia
+sol = sim(
+    scen; 
+    alg = Rodas5P(),
+    reltol=1e-6,
+    abstol=1e-8
+)
+```
+
 The following [DiffEq Docs page](https://docs.sciml.ai/DiffEqDocs/stable/solvers/ode_solve/) provides general advice on how to choose a solver suitable for your ODE system. 
 For many ODE systems the following simplified guideline is sufficient:
 1. If your system is small (~10 ODEs) go with the default solver 
-2. If the system is large and stiff choose `FBDF()` or `QNDF()`
-3. If `FBDF()` fails to solve the system check the model and try it again :)
-4. If `FBDF()` still fails to solve the system or the integration takes too long try `CVODE_BDF()`*
+2. If your system is medium-sized (~50 ODEs) choose `Rodas5P()`
+3. If the system is large and stiff choose `FBDF()` or `QNDF()`
+4. If `FBDF()` fails to solve the system check the model and try it again :)
+5. If `FBDF()` still fails to solve the system or the integration takes too long try `CVODE_BDF()`*
 
 *You should be cautious when using `CVODE_BDF()`. In many cases it is the fastest solver, however the accuracy of the solution is often the tradeoff. You shouldn't use it with tolerances higher than ~ `reltol=1e-4` and `abstol=1e-7`.