Topic sample template

[jrakibi]

This PR addresses #1 and #2

This template can be used for each topic in this repo, and it will be consumed and parsed by the [BDP website] (https://bitcoindevs.xyz/).

Key Features:

• Metadata: Includes title, tags, excerpt, author details, related topics, references, featured image.
• SEO Metadata: Includes keywords, canonical URL, and Open Graph tags to improve search engine visibility, indexing, and display in search results and social media previews.
• Excerpt: will be used by other BDP products (Bitcoin Search, ChatBTC) to provide an overview of the topic and backlink it to the main BDP website.
• Expandable/Collapsible Sections: These sections are optional and will be used for curious readers who want to dive deeper into explanations.

I've already used this template to display the UI we showed in the previous demo for Payjoin. However, am still having issues using default GitHub Markdown (.md) to parse and embed custom components (like expandable/collapsible ones) without relying on MDX. Therefore, I've marked this PR as a draft until I come up with a final version that is easy to parse and allows for smooth embedding of custom components.

[jrakibi]

@Extheoisah @kouloumos appreciate another round of review. Following this format, we’re able to pull content from this repo to our BDP website, extract and parse all necessary information, including embedded components, images, ... and display them