Added electrical example and icons

Author: Brad Carman

README.md

@@ -1,8 +1,17 @@
 # ModelingToolkitDesigner.jl
 
-The ModelingToolkitDesigner.jl package is a helper tool for visualizing and editing ModelingToolkit.jl system connections.  An example system visualization generated from this package is shown below
+The ModelingToolkitDesigner.jl package is a helper tool for visualizing and editing ModelingToolkit.jl system connections.  
 
-![example](https://user-images.githubusercontent.com/40798837/228676202-c13b93c2-d023-4b00-bed8-c8440cb8ca57.png)
+## Examples
+Examples can be found in the "examples" folder.
+
+### Hydraulic Example
+
+![example1](https://user-images.githubusercontent.com/40798837/228676202-c13b93c2-d023-4b00-bed8-c8440cb8ca57.png)
+
+### RC Circuit Example
+
+![example2](examples/electrical.svg)
 
 
 # Tutorial

examples/design/Main/Circuit.jl

@@ -0,0 +1,5 @@
+connect(constant.output, source.V)
+connect(source.p, resistor.p)
+connect(resistor.n, capacitor.p)
+connect(capacitor.n, source.n)
+connect(source.n, ground.g)

examples/design/Main/Circuit.toml

@@ -0,0 +1,24 @@
+[capacitor]
+n = "S"
+x = 0.52
+y = 0.29
+
+[constant]
+x = 0.54
+y = -0.03
+
+[ground]
+x = 0.43
+y = 0.11
+
+[resistor]
+n = "W"
+p = "S"
+x = 0.8
+y = 0.29
+
+[source]
+V = "S"
+n = "W"
+x = 0.66
+y = 0.11

examples/electrical.jl

@@ -0,0 +1,39 @@
+using ModelingToolkit
+using ModelingToolkitStandardLibrary.Electrical
+using ModelingToolkitStandardLibrary.Blocks: Constant
+using ModelingToolkitDesigner
+using CairoMakie
+
+@component function Circuit(;name)
+
+    R = 1.0
+    C = 1.0
+    V = 1.0
+    @variables t
+    systems = @named begin
+        resistor = Resistor(R = R)
+        capacitor = Capacitor(C = C)
+        source = Voltage()
+        constant = Constant(k = V)
+        ground = Ground()    
+    end
+    
+
+    eqs = [connect(constant.output, source.V)
+            connect(source.p, resistor.p)
+            connect(resistor.n, capacitor.p)
+            connect(capacitor.n, source.n, ground.g)]
+
+    ODESystem(eqs, t, [], [];  systems, name)
+end
+
+@named rc = Circuit()
+
+
+path = joinpath(@__DIR__, "design")
+design = ODESystemDesign(rc, path)
+ModelingToolkitDesigner.view(design)
+
+CairoMakie.set_theme!(Theme(;fontsize=12))
+fig = ModelingToolkitDesigner.view(design, false)
+save(joinpath(@__DIR__, "electrical.svg"), fig; resolution=(400,400))