add cypress tests for admin text summary page

cypress/e2e/admin.cy.js

@@ -1,7 +1,24 @@
 describe('The admin page', () => {
-  it('successfully loads texts', () => {
+  beforeEach(() => {
     cy.visit('/admin')
-      cy.get('#newTextname').type('new text')
+  })
+
+  it('navigates to texts page', () => {
+    cy.get('#texts').click()
+    cy.url().should('include', '/admin/texts')
+  })
+
+  it('shows texts page with heading and form', () => {
+    cy.visit('/admin/texts')
+    cy.get('h1').should('contain', 'Texts')
+    cy.get('#newTextName').should('exist')
+    cy.get('#submit').should('exist')
+  })
+
+  it('creates a new text', () => {
+    cy.visit('/admin/texts')
+    cy.get('#newTextName').type('Test Text')
     cy.get('#submit').click()
+    cy.contains('Test Text')
   })
 })