Add local documentation infrastructure (#235)

Signed-off-by: Jack Baldry <jack.baldry@grafana.com>

Author: jdbaldry

docs/Makefile

@@ -0,0 +1,8 @@
+.ONESHELL:
+.DELETE_ON_ERROR:
+export SHELL     := bash
+export SHELLOPTS := pipefail:errexit
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rule
+
+include docs.mk

docs/docs.mk

@@ -0,0 +1,115 @@
+# The source of this file is https://raw.githubusercontent.com/grafana/writers-toolkit/main/docs/docs.mk.
+# A changelog is included in the head of the `make-docs` script.
+include variables.mk
+-include variables.mk.local
+
+.ONESHELL:
+.DELETE_ON_ERROR:
+export SHELL     := bash
+export SHELLOPTS := pipefail:errexit
+MAKEFLAGS += --warn-undefined-variables
+MAKEFLAGS += --no-builtin-rule
+
+.DEFAULT_GOAL: help
+
+# Adapted from https://www.thapaliya.com/en/writings/well-documented-makefiles/
+.PHONY: help
+help: ## Display this help.
+help:
+	@awk 'BEGIN { \
+		FS = ": ##"; \
+		printf "Usage:\n  make <target>\n\nTargets:\n" \
+	} \
+	/^[a-zA-Z0-9_\.\-\/%]+: ##/ { printf "  %-15s %s\n", $$1, $$2 }' \
+	$(MAKEFILE_LIST)
+
+GIT_ROOT := $(shell git rev-parse --show-toplevel)
+
+PODMAN := $(shell if command -v podman >/dev/null 2>&1; then echo podman; else echo docker; fi)
+
+ifeq ($(PROJECTS),)
+$(error "PROJECTS variable must be defined in variables.mk")
+endif
+
+# Host port to publish container port to.
+ifeq ($(origin DOCS_HOST_PORT), undefined)
+export DOCS_HOST_PORT := 3002
+endif
+
+# Container image used to perform Hugo build.
+ifeq ($(origin DOCS_IMAGE), undefined)
+export DOCS_IMAGE := grafana/docs-base:latest
+endif
+
+# Container image used for Vale linting.
+ifeq ($(origin VALE_IMAGE), undefined)
+export VALE_IMAGE := grafana/vale:latest
+endif
+
+# PATH-like list of directories within which to find projects.
+# If all projects are checked out into the same directory, ~/repos/ for example, then the default should work.
+ifeq ($(origin REPOS_PATH), undefined)
+export REPOS_PATH := $(realpath $(GIT_ROOT)/..)
+endif
+
+# How to treat Hugo relref errors.
+ifeq ($(origin HUGO_REFLINKSERRORLEVEL), undefined)
+export HUGO_REFLINKSERRORLEVEL := WARNING
+endif
+
+# Whether to pull the latest container image before running the container.
+ifeq ($(origin PULL), undefined)
+export PULL := true
+endif
+
+.PHONY: docs-rm
+docs-rm: ## Remove the docs container.
+	$(PODMAN) rm -f $(DOCS_CONTAINER)
+
+.PHONY: docs-pull
+docs-pull: ## Pull documentation base image.
+	$(PODMAN) pull -q $(DOCS_IMAGE)
+
+make-docs: ## Fetch the latest make-docs script.
+make-docs:
+	if [[ ! -f "$(CURDIR)/make-docs" ]]; then
+		echo 'WARN: No make-docs script found in the working directory. Run `make update` to download it.' >&2
+		exit 1
+	fi
+
+.PHONY: docs
+docs: ## Serve documentation locally, which includes pulling the latest `DOCS_IMAGE` (default: `grafana/docs-base:latest`) container image. To not pull the image, set `PULL=false`.
+ifeq ($(PULL), true)
+docs: docs-pull make-docs
+else
+docs: make-docs
+endif
+	$(CURDIR)/make-docs $(PROJECTS)
+
+.PHONY: docs-debug
+docs-debug: ## Run Hugo web server with debugging enabled. TODO: support all SERVER_FLAGS defined in website Makefile.
+docs-debug: make-docs
+	WEBSITE_EXEC='hugo server --bind 0.0.0.0 --port 3002 --logLevel debug' $(CURDIR)/make-docs $(PROJECTS)
+
+.PHONY: vale
+vale: ## Run vale on the entire docs folder which includes pulling the latest `VALE_IMAGE` (default: `grafana/vale:latest`) container image. To not pull the image, set `PULL=false`.
+vale: make-docs
+ifeq ($(PULL), true)
+	$(PODMAN) pull -q $(VALE_IMAGE)
+endif
+	DOCS_IMAGE=$(VALE_IMAGE) $(CURDIR)/make-docs $(PROJECTS)
+
+.PHONY: update
+update: ## Fetch the latest version of this Makefile and the `make-docs` script from Writers' Toolkit.
+	curl -s -LO https://raw.githubusercontent.com/grafana/writers-toolkit/main/docs/docs.mk
+	curl -s -LO https://raw.githubusercontent.com/grafana/writers-toolkit/main/docs/make-docs
+	chmod +x make-docs
+
+# ls static/templates/ | sed 's/-template\.md//' | xargs
+TOPIC_TYPES := concept multiple-tasks reference section task tutorial visualization
+.PHONY: $(patsubst %,topic/%,$(TOPIC_TYPES))
+topic/%: ## Create a topic from the Writers' Toolkit template. Specify the topic type as the target, for example, `make topic/task TOPIC_PATH=sources/my-new-topic.md`.
+$(patsubst %,topic/%,$(TOPIC_TYPES)):
+	$(if $(TOPIC_PATH),,$(error "You must set the TOPIC_PATH variable to the path where the $(@F) topic will be created. For example: make $(@) TOPIC_PATH=sources/my-new-topic.md"))
+	mkdir -p $(dir $(TOPIC_PATH))
+	curl -s -o $(TOPIC_PATH) https://raw.githubusercontent.com/grafana/writers-toolkit/refs/heads/main/docs/static/templates/$(@F)-template.md