Ledgers page index.html redirect (#1022)

## High Level Overview of Change
Obseleted path (/index.html) now redirects to current path to ledgers
page (/).

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### Context of Change

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### Type of Change

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- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
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- [ ] Refactor (non-breaking change that only restructures code)
- [ ] Tests (You added tests for code that already exists, or your new
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- [ ] Documentation Updates
- [ ] Translation Updates
- [ ] Release

### TypeScript/Hooks Update

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## Before / After

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## Test Plan

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src/containers/App/index.tsx

@@ -104,6 +104,14 @@ export const AppWrapper = () => {
                   path={updatePath('/ledgers')}
                   element={<Navigate to={updatePath('/')} replace />}
                 />
+                <Route
+                  path={updatePath('/index.html')}
+                  element={<Navigate to={updatePath('/')} replace />}
+                />
+                <Route
+                  path={updatePath('/index.htm')}
+                  element={<Navigate to={updatePath('/')} replace />}
+                />
                 {/* End: Redirects */}
                 {mode === 'custom' && (
                   <Route path="/" element={<CustomNetworkHome />} />

src/containers/App/test/App.test.jsx

@@ -161,6 +161,40 @@ describe('App container', () => {
     ])
   })
 
+  it('renders ledger explorer page from index.html redirect', async () => {
+    wrapper = createWrapper('/index.html')
+    await flushPromises()
+    await flushPromises()
+    wrapper.update()
+
+    expect(document.title).toEqual('xrpl_explorer | ledgers')
+    expect(window.dataLayer).toEqual([
+      {
+        page_path: '/',
+        page_title: `xrpl_explorer | ledgers`,
+        event: 'screen_view',
+        network: 'mainnet',
+      },
+    ])
+  })
+
+  it('renders ledger explorer page from index.htm redirect', async () => {
+    wrapper = createWrapper('/index.html')
+    await flushPromises()
+    await flushPromises()
+    wrapper.update()
+
+    expect(document.title).toEqual('xrpl_explorer | ledgers')
+    expect(window.dataLayer).toEqual([
+      {
+        page_path: '/',
+        page_title: `xrpl_explorer | ledgers`,
+        event: 'screen_view',
+        network: 'mainnet',
+      },
+    ])
+  })
+
   it('renders not found page', () => {
     wrapper = createWrapper('/zzz')
     return new Promise((r) => setTimeout(r, 10)).then(() => {