Update index.md

Author: ChrisRackauckas

docs/src/index.md

@@ -41,6 +41,31 @@ prob = ODEProblem(rober, [1.0, 0.0, 0.0], (0.0, 1e5), [0.04, 3e7, 1e4])
 sol = solve(prob)
 ```
 
+### Latex
+
+Latexify directly works on the generated expression. Example:
+
+```julia
+using ParameterizedFunctions, Latexify
+
+lotka_volterra = @ode_def begin
+    dx = a*x -b*x*y
+    dy = -c*y + d*x*y
+end a b c d
+
+latexify(lotka_volterra.sys)
+```
+
+Generates:
+
+```julia
+L"\begin{align}
+\frac{\mathrm{d} x\left( t \right)}{\mathrm{d}t} =& a x\left( t \right) - b x\left( t \right) y\left( t \right) \\
+\frac{\mathrm{d} y\left( t \right)}{\mathrm{d}t} =&  - c y\left( t \right) + d x\left( t \right) y\left( t \right)
+\end{align}
+"`
+```
+
 ## Contributing
 
   - Please refer to the