Support for SSG-style vault exports

[SakuraIsayeki]

Context

As a web developer using other technologies outside of the .NET ecosystem, I should be able to export a MoltenObsidian vault into static HTML files, for use in my non-ASP.NET apps.

Solution

Overview

We should implement a CLI tool (or more exactly integrate with the existing one) that allows a MO Vault to HTML output.

Requirements

• The core pipeline consists of first instantiating a vault, through FS or HTTP, then rendering ahead-of-time all vault notes and bundling related assets (like media attachments, etc), and perhaps manifest.
• The tool command should be invoked as either :
  • moltenobsidian ssg generate --from-folder "/path/to/vault/"
  • moltenobsidian ssg generate --from-url "https://path.to/vault/moltenobsidian.manifest.json"
• Support for render options, such as Bootstrap support and Dark Mode support, should be supported.
• Support for YAML Frontmatter export should be supported, through a separate export to a .yaml file.
• Support for output packing/bundling to Gzip/Bzip should be supported, at term (see #4).

[SakuraIsayeki]

With PR #22 implementing the core of the SSG export feature, we're now still missing the YAML Frontmatter export.
This should be a relatively straightforward task. Updated the issue description.