Task: Generate dynamic contents for EMAILS or HTML pages

n8n workflow:
{"meta":{"instanceId":"14c5980141526fbb38db85208103f515afa76de9c8760a23a1771b4ed940dc7b"},"nodes":[{"id":"4704e44a-80c6-41b4-a0b9-ece060d53836","name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[-220,300],"parameters":{},"typeVersion":1},{"id":"74a78b35-b453-4345-8cd9-9d8a62961c29","name":"Customer Datastore","type":"n8n-nodes-base.n8nTrainingCustomerDatastore","position":[20,300],"parameters":{"operation":"getAllPeople","returnAll":true},"typeVersion":1},{"id":"10b633de-e5e5-4fd2-bb4b-7a16bac5f69c","name":"Item Lists","type":"n8n-nodes-base.itemLists","position":[220,300],"parameters":{"options":{},"operation":"sort","sortFieldsUi":{"sortField":[{"fieldName":"name"}]}},"typeVersion":1},{"id":"aa90be4e-f548-459f-822b-a3dc1d20d58e","name":"One item per template","type":"n8n-nodes-document-generator.DocumentGenerator","position":[660,160],"parameters":{"template":"Date: {{created}}\nTo: {{name}} <{{email}}>\nAddress: {{country}}\nDetails:\n{{#each lines}}\n- \"{{description}}\" x {{quantity}} = {{amount}}€ + {{vat}}€ = {{total}}€\n{{/each}}\nTotal invoice: {{total}}€"},"typeVersion":1},{"id":"914c4c67-81df-45ec-9eea-3efb96383dfc","name":"All items, one template","type":"n8n-nodes-document-generator.DocumentGenerator","position":[660,400],"parameters":{"template":"<html>\n<head>\n</head>\n<body>\nNew customers in last 24h:\n<ul id=\"customer_list\">\n  {{#each items}}\n  <li>{{name}}: {{email}}</li>\n  {{/each}}\n</ul>\n</body>\n</html>","oneTemplate":true},"typeVersion":1},{"id":"bc1821d1-7d08-4208-aa5e-7290f5604e91","name":"Add lines","type":"n8n-nodes-base.functionItem","position":[440,160],"parameters":{"functionCode":"item.lines = [\n  {\n    concept: \"Service\",\n    description: \"Design of HTML banners\",\n    quantity: 1,\n    amount: 22,\n    vat: 22 * 0.21,\n    total: 22 * 1.21\n  },\n  {\n    concept: \"Service\",\n    description: \"Design of PNG banners\",\n    quantity: 1,\n    amount: 33,\n    vat: 33 * 0.21,\n    total: 33 * 1.21\n  }\n]\n\nitem.date = \"2022-01-12\";\nitem.total = 133.10;\n\nreturn item;"},"typeVersion":1},{"id":"99ccf5f0-6d82-4a9c-a314-711249fbdfc9","name":"Send one TEXT email per item","type":"n8n-nodes-base.emailSend","position":[880,160],"parameters":{"html":"={{ $json[\"text\"] }}","options":{},"subject":"=Invoice for {{ $node[\"Add lines\"].json[\"name\"] }}","toEmail":"mcolomer@n8nhackers.com","fromEmail":"mcolomer@n8nhackers.com"},"credentials":{"smtp":{"id":"54","name":"SMTP account"}},"typeVersion":1},{"id":"3bc12345-da46-4c1f-8fe3-5bb0683cbcda","name":"Send one HTML Email per list","type":"n8n-nodes-base.emailSend","position":[880,400],"parameters":{"html":"={{ $json[\"text\"] }}","options":{},"subject":"New customers","toEmail":"mcolomer@n8nhackers.com","fromEmail":"mcolomer@n8nhackers.com"},"credentials":{"smtp":{"id":"54","name":"SMTP account"}},"typeVersion":1}],"connections":{"Add lines":{"main":[[{"node":"One item per template","type":"main","index":0}]]},"Item Lists":{"main":[[{"node":"All items, one template","type":"main","index":0},{"node":"Add lines","type":"main","index":0}]]},"Customer Datastore":{"main":[[{"node":"Item Lists","type":"main","index":0}]]},"On clicking 'execute'":{"main":[[{"node":"Customer Datastore","type":"main","index":0}]]},"One item per template":{"main":[[{"node":"Send one TEXT email per item","type":"main","index":0}]]},"All items, one template":{"main":[[{"node":"Send one HTML Email per list","type":"main","index":0}]]}}}