Add misses-rt crate, component example, README, and fix codegen for non-keyword literal tokens

- misses-rt: add Buffer/Markup HTML helpers, name/type helpers, parse_sections/parse_kv, and template AST
- codegen: add is_syn_keyword() — non-keyword idents in patterns now generate parse+compare instead of syn::Token![…]
- parser: split punct vs ident chars in literal pattern tokens so `props:` becomes two tokens
- examples: add component.mrs/.rs demonstrating named literal tokens and tt capture
- README: comprehensive guide covering .mrs syntax, running the compiler, misses-rt helpers, and examples

https://claude.ai/code/session_01Tppkab4eLsL21asHGjQJoF

misses-compiler/examples/component.rs

@@ -0,0 +1,8 @@
+fn main() {
+    let source = include_str!("component.mrs");
+    println!("=== SOURCE ===\n{source}");
+
+    let file = misses::parse(source).expect("parse error");
+    let generated = misses::codegen(&file);
+    println!("=== GENERATED ===\n{generated}");
+}