Follow upstream

# Conflicts:
#	README.md
#	_examples/custom-handler/main.go
#	_examples/custom-method/main.go
#	_examples/fileserver/main.go
#	_examples/hello-world/main.go
#	_examples/limits/main.go
#	_examples/router-walk/main.go
#	_examples/todos-resource/main.go
#	_examples/todos-resource/todos.go
#	_examples/todos-resource/users.go
#	chain.go
#	chi.go
#	context.go
#	go.mod
#	middleware/basic_auth.go
#	middleware/profiler.go
#	middleware/throttle.go
#	mux.go
#	mux_test.go
#	tree.go
#	tree_test.go

Upgrade chi

# Conflicts:
#	.github/workflows/ci.yml
#	Makefile
#	README.md
#	_examples/todos-resource/users.go
#	middleware/realip.go
#	middleware/realip_test.go
#	middleware/recoverer.go
#	mux_test.go

Merge upstream