feat(examples): Add Gno Package for Markdown Rendering

[thanhngoc541]

Related to #2753

This pull request introduces a new Gno package that utilizes the blackfriday library to render Markdown into HTML.

Supported Markdown Syntax:

• Headers (#, ##, ###, etc.)
• Lists (ordered and unordered)
• Links and Images
• Code blocks and inline code
• Emphasis (bold and italic)
• Blockquotes

func RenderExampleHeader() string {
	input := `
# Heading Level 1
## Heading Level 2
### Heading Level 3
#### Heading Level 4
##### Heading Level 5
###### Heading Level 6
`
	out := runMarkdown(input)
	return out
}

func RenderExampleLists() string {
	input := `
# Unordered List

* Item 1
    * Subitem 1.1
    	* Subitem 1.1.1
* Item 2
    * Subitem 2.1
    	* Subitem 2.1.1


# Ordered List

1. First item
   1. Subitem 1.1
      1. Subitem 1.1.1
2. Second item
   1. Subitem 2.1
      1. Subitem 2.1.1
`

	out := runMarkdown(input)

	return out
}

func RenderExampleLinkAndImage() string {
	input := `
# Link And Image
Here is a [link to VarMeta](https://www.var-meta.com/).
![Gno logo](https://www.var-meta.com/favicon-16x16.png)
`

	out := runMarkdown(input)

	return out
}

func RenderExampleCode() string {
	input := `# Code Block
Here is an inline code example: ` + "`" + `fmt.Println("Hello Gno!")` + "`" + `.

` + "``` go\n" + `func foo() bool {
	return true;
	}
` + "```\n"

	out := runMarkdown(input)

	return out
}

func RenderExampleEmphasis() string {
	input := `# Emphasis
This is **bold** text, and this is _italic_ text.
`
	out := runMarkdown(input)
	return out
}

func RenderExampleBlockquote() string {
	input := `# Blockquote #
> This is a blockquote.

> Here is another blockquote with **bold** and _italic_ text.
`

	out := runMarkdown(input)

	return out
}

func RenderExampleTable() string {
	input := `# Table
| Header 1 | Header 2 |
| -------- | -------- |
| Cell 1   | Cell 2   |
| Cell 3   | Cell 4   |
`
	out := runMarkdown(input)
	return out
}

Contributors' checklist...

• Added new tests, or not needed, or not feasible
• Provided an example (e.g. screenshot) to aid review or the PR is self-explanatory
• Updated the official documentation or not needed
• No breaking changes were made, or a BREAKING CHANGE: xxx message was included in the description
• Added references to related issues and PRs
• Provided any useful hints for running manual tests
• Added new benchmarks to generated graphs, if any. More info here.

[thinhnx-var]

@moul @leohhhn
We are pushing more usage examples to indicate what this package can do.
Could you take a look on this PR and give us review if we are going into right approach or not?