Drop Markdown Support

[shadowtime2000]

I feel like automatically converting markdown into a React component may not be that good of an idea. First of all, it makes AlephJS more opinionated than it needs to be. Second, some people (like me) want to separate content from code. I wouldn't want to create a blog post in pages/blog/my-blog-post.md but rather in posts/my-blog-post.md with pages/blog/$post automatically loading it.

[mohsenkhanpour]

I think markdown support is a great idea. Aleph docs are written in markdown.
It would be a great idea to support .mdx and .html too.
I also agree with @shadowtime2000 pages directory seems to be redundant. I think it would be a good idea to add a input option to cli like aleph --input=. --output=_dist --ext=md,tsx and also to aleph.config.js to handle the input directory.
Also it would be a good idea to choose layout for markdown pages in frontmatter.

[ije]

@shadowtime2000 @mohsenkhanpour i alreay dropped it in 8162d2f , and i added a new ServePlugin type to allow us to add custom page modules like markdown:

export default {
    type: 'server'
    onInit(app: ServerApplication): {
        for await (const { path: p, } of walk(path.join(app.workingDir, 'docs'), { exts: ['.md', '.markdown'] })) {
            app.addPageModule('/docs/' + p.split('/docs/')[1].replace(/\.md$/, ''), toJs(Deno.readTextFileSync(p)))
        }
        // todo: watch md files...
    }
}