Migrate website to Hugo

Signed-off-by: Luc Perkins <lucperkins@gmail.com>

docs/Makefile

@@ -0,0 +1,31 @@
+#   Copyright The containerd Authors.
+
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+
+#       http://www.apache.org/licenses/LICENSE-2.0
+
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+HUGO = hugo
+BASE_URL = https://containerd.io
+
+clean:
+	rm -rf public
+
+build: clean
+	$(HUGO) \
+		--baseURL $(BASE_URL)
+
+build-preview: clean
+	$(HUGO)
+
+dev: clean
+	$(HUGO) server \
+		--disableFastRender \
+		--ignoreCache