chore(corp/rih): move frontend to a separate folder

Change-Id: Ic7467f459015c39c73f87c61a048319eaf1243be
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8714
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

corp/rih/frontend/static-markdown/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+version = "1.0.0"
+name = "static_markdown"
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+syn = "1.0"
+quote = "1.0"
+comrak = "0.18"

corp/rih/frontend/static-markdown/src/lib.rs

@@ -0,0 +1,27 @@
+extern crate proc_macro;
+
+use comrak::{markdown_to_html, ComrakOptions};
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{parse_macro_input, LitStr};
+
+#[proc_macro]
+pub fn markdown(input: TokenStream) -> TokenStream {
+    let input = parse_macro_input!(input as LitStr);
+
+    let mut options = ComrakOptions::default();
+    options.extension.strikethrough = true;
+    options.extension.tagfilter = true;
+    options.extension.table = true;
+    options.extension.autolink = true;
+
+    let rendered_html = markdown_to_html(&input.value(), &options);
+
+    let tokens = quote! {
+        yew::virtual_dom::VNode::VRaw(yew::virtual_dom::VRaw {
+            html: #rendered_html.into(),
+        })
+    };
+
+    tokens.into()
+}