Makefile for php-src docs build

In 19d2b84 ("Create book for docs", 2024-01-30) the php-src
documentation (php-src docs) build has been introduced, yet the build
instructions, namely `make html`, did not yield the expected results
within the parenting setup of the php-src project on *nix systems.

The reason is that the `make html` build instruction does not execute
the make.bat file which contains the recipe to build the static HTML
pages.

It is an unused leftover file from initializing the project with
sphinx-quickstart. [1]

Removing it in and adding a Makefile suffices to recover the build of
php-src ./docs on a *nix system.

Formatting constraints checked in the docs workflow in CI update
use the make file to make sure the commands stay consistent and the
build is managed by the build manager.

[1]: https://www.sphinx-doc.org/en/master/man/sphinx-quickstart.html "sphinx-quickstart is an interactive tool that asks some questions about your project and then generates a complete documentation directory and sample Makefile to be used with sphinx-build(1)."

Author: hakre

.github/workflows/docs.yml

@@ -21,7 +21,7 @@ jobs:
       - name: Install dependencies
         run: pip install sphinx-design sphinxawesome-theme rstfmt
       - name: Check formatting
-        run: rstfmt --check -w 100 docs/source
+        run: make -C docs check-formatting
       - name: Publish
         if: github.event_name == 'push'
         uses: sphinx-notes/pages@v3

docs/Makefile

@@ -0,0 +1,36 @@
+# Makefile for php-src/docs
+# Copyright (c) The PHP Group
+
+# If people set these on the make command line, use 'em
+
+SPHINXBUILD ?= sphinx-build
+
+SOURCEDIR = source
+BUILDDIR = build
+RSTFMT = rstfmt
+RSTFMTFLAGS = -w 100
+
+rwildcard = $(foreach d,$(wildcard $(1:=/*)),$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d))
+FILES = $(call rwildcard,$(SOURCEDIR),*.rst)
+
+all : html
+
+.PHONY : check-formatting clean html preflight
+.SUFFIXES : # Disable legacy behavior
+
+check-formatting :
+	$(RSTFMT) $(RSTFMTFLAGS) --check $(SOURCEDIR)
+
+clean :
+	rm -rf -- $(wildcard $(SOURCEDIR)/.~ $(BUILDDIR))
+
+html : preflight
+	$(SPHINXBUILD) -M $@ $(SOURCEDIR) $(BUILDDIR)
+	@printf 'Browse the \e]8;;%s\e\\%s\e]8;;\e\\.\n' \
+		"file://$(abspath $(BUILDDIR))/$@/index.$@" "php-src html docs locally"
+
+preflight : $(SOURCEDIR)/.~
+
+$(SOURCEDIR)/.~ : $(FILES)
+	$(RSTFMT) $(RSTFMTFLAGS) $?
+	touch $@