docs: add user-facing Handlebars chart page with full helpers reference (#39591)

Co-authored-by: Emmanuela Opurum <youremail@example.com>

superset-frontend/plugins/plugin-chart-handlebars/src/plugin/controls/handlebarTemplate.tsx

@@ -1,4 +1,4 @@
-/**
+/**
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
@@ -24,7 +24,7 @@ import {
 import { t } from '@apache-superset/core/translation';
 import { validateNonEmpty } from '@superset-ui/core';
 import { useTheme } from '@apache-superset/core/theme';
-import { InfoTooltip, SafeMarkdown } from '@superset-ui/core/components';
+import { InfoTooltip } from '@superset-ui/core/components';
 import { CodeEditor } from '../../components/CodeEditor/CodeEditor';
 import { ControlHeader } from '../../components/ControlHeader/controlHeader';
 import { debounceFunc } from '../../consts';
@@ -37,36 +37,10 @@ const HandlebarsTemplateControl = (
   props: CustomControlConfig<HandlebarsCustomControlProps>,
 ) => {
   const theme = useTheme();
-
   const val = String(
     props?.value ? props?.value : props?.default ? props?.default : '',
   );
 
-  const helperDescriptionsHeader = t(
-    'Available Handlebars Helpers in Superset:',
-  );
-
-  const helperDescriptions = [
-    { key: 'dateFormat', descKey: 'Formats a date using a specified format.' },
-    { key: 'stringify', descKey: 'Converts an object to a JSON string.' },
-    {
-      key: 'formatNumber',
-      descKey: 'Formats a number using locale-specific formatting.',
-    },
-    {
-      key: 'parseJson',
-      descKey: 'Parses a JSON string into a JavaScript object.',
-    },
-  ];
-
-  const helpersTooltipContent = `
-${helperDescriptionsHeader}
-
-${helperDescriptions
-  .map(({ key, descKey }) => `- **${key}**: ${t(descKey)}`)
-  .join('\n')}
-`;
-
   return (
     <div>
       <ControlHeader>
@@ -74,7 +48,7 @@ ${helperDescriptions
           {props.label}
           <InfoTooltip
             iconStyle={{ marginLeft: theme.sizeUnit }}
-            tooltip={<SafeMarkdown source={helpersTooltipContent} />}
+            tooltip={<span>{t('See ')} <a href="https://superset.apache.org/docs/using-superset/handlebars-chart" target="_blank" rel="noopener noreferrer">{t('the Handlebars chart documentation')}</a> {t('for a list of available helpers.')}</span>}
           />
         </div>
       </ControlHeader>
@@ -104,7 +78,6 @@ export const handlebarsTemplateControlSetItem: ControlSetItem = {
     isInt: false,
     renderTrigger: true,
     valueKey: null,
-
     validators: [validateNonEmpty],
     mapStateToProps: ({ form_data }) => ({
       value: form_data?.handlebarsTemplate ?? form_data?.handlebars_template,