docs: add tag names as second column in README component tables

[Copilot]

Enhanced the README component documentation by adding HTML tag names as the second column in both component summary tables. This makes it easier for developers to understand the mapping between component class names and their corresponding custom element tags.

Changes:

• Store level templating table: Added tag names for Campaign (nosto-campaign), SectionCampaign (nosto-section-campaign), and Control (nosto-control)
• Campaign level templating table: Added tag names for DynamicCard (nosto-dynamic-card), Image (nosto-image), Product (nosto-product), ProductCard (nosto-product-card), and SkuOptions (nosto-sku-options)

Before:

| Component | Description |
| --------- | ----------- |
| Campaign  | Campaign rendering and product recommendation display |

After:

| Component | Tag Name         | Description |
| --------- | ---------------- | ----------- |
| Campaign  | `nosto-campaign` | Campaign rendering and product recommendation display |

All tag names were verified against the actual @customElement decorators in the source code to ensure accuracy. The tag names are formatted with code blocks (backticks) for better visual distinction.

Fixes #295.

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[Copilot]

Pull Request Overview

This PR enhances the README documentation by adding HTML tag names as a second column in both component summary tables, making it easier for developers to understand the mapping between component class names and their corresponding custom element tags.

Key changes:

• Added "Tag Name" column to both store-level and campaign-level component tables
• Included proper HTML custom element tag names for all 8 components
• Formatted tag names with code blocks for better visual distinction