Add capacitance calc to html

.gitignore

@@ -1 +1,3 @@
+.DS_Store
+
 /target

tests/draw.html

@@ -110,7 +110,8 @@
                 }
 
 
-                console.log()
+                let cap = -0.5 / (22000 * Math.log(min/max));
+                console.log(`Calculated capacitance: ${cap}`);
             }
 
             function GetYForData(val) {