feat: initial implementation of go-kite

Core framework:
- Kite router with full HTTP method support (GET, POST, PUT, DELETE, HEAD, OPTIONS, CONNECT, TRACE)
- Nestable route groups with prefix and middleware inheritance
- Global, group, and route-level middleware with onion ordering
- Centralized error, not-found, and method-not-allowed handlers
- Graceful shutdown on SIGTERM/SIGINT with configurable timeout
- Configurable server read, write, and idle timeouts
- Context with typed request/response helpers, value store, cookie, form, and body binding support
- Response writer wrapper for status code tracking

Middleware:
- Logger with configurable output, format, and skip function
- Recovery with configurable panic handler
- RequestID with configurable header and generator, forwards incoming IDs
- CORS with configurable origins, methods, headers, credentials, and max age
- MaxBodySize with configurable byte limit

Docs:
- README with quickstart, routing, middleware, context API reference, and TLS guide

group.go

@@ -0,0 +1,57 @@
+package kite
+
+import "net/http"
+
+type Group struct {
+	k      *Kite
+	prefix string
+	mws    []Middleware
+}
+
+func (g *Group) Group(prefix string, mws ...Middleware) *Group {
+	return &Group{
+		k:      g.k,
+		prefix: g.prefix + prefix,
+		mws:    append(append([]Middleware{}, g.mws...), mws...),
+	}
+}
+
+func (g *Group) Use(mws ...Middleware) {
+	g.mws = append(g.mws, mws...)
+}
+
+func (g *Group) CONNECT(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodConnect, path, h, mws...)
+}
+
+func (g *Group) DELETE(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodDelete, path, h, mws...)
+}
+
+func (g *Group) GET(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodGet, path, h, mws...)
+}
+
+func (g *Group) HEAD(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodHead, path, h, mws...)
+}
+
+func (g *Group) OPTIONS(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodOptions, path, h, mws...)
+}
+
+func (g *Group) POST(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodPost, path, h, mws...)
+}
+
+func (g *Group) PUT(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodPut, path, h, mws...)
+}
+
+func (g *Group) TRACE(path string, h Handler, mws ...Middleware) {
+	g.handle(http.MethodTrace, path, h, mws...)
+}
+
+func (g *Group) handle(method, path string, h Handler, mws ...Middleware) {
+	g.k.handle(method, g.prefix+path, h, append(g.mws, mws...)...)
+}