fix: Mark chart with @State to prevent HMR bug

see ionic-team/stencil#1316 for ref

src/components/apex-chart/apex-chart.tsx

@@ -1,4 +1,4 @@
-import { Component, Prop } from '@stencil/core';
+import { Component, Prop, State } from '@stencil/core';
 import ApexCharts from 'apexcharts';
 
 @Component({
@@ -8,13 +8,15 @@ import ApexCharts from 'apexcharts';
 })
 export class chart {
   el: HTMLElement;
-  chart: ApexCharts = null;
+  @State() chart: ApexCharts = null;
 
   @Prop() options: object = {}
 
   componentDidLoad() {
-    this.chart = new ApexCharts(this.el, this.options);
-    return this.chart.render();
+    if (this.chart === null) {
+      this.chart = new ApexCharts(this.el, this.options);
+      return this.chart.render();  
+    }
   }
 
   componentDidUnload()  {