Add workflow for building documentation (#872)

* .github/workflows/docs.yml: New workflow
* Makefile (TEXICMD): Fail build on errors
    (doc-clean): Use make foreach for removing doc build artifacts. (Avoid
    bash brace expansion.) Remove README.md.html and README.toc.md.

Author: matsl

.github/workflows/docs.yml

@@ -0,0 +1,34 @@
+# .github/workflows/docs.yml
+name: Build Docs
+
+on:
+  pull_request:
+    branches:
+      - master
+    paths:
+      - 'man/**'
+      - '**.md'
+
+jobs:
+  build-docs:
+    runs-on: ubuntu-latest
+    container:
+      image: ubuntu:24.04
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          apt-get update
+          apt-get install -y \
+            make \
+            pandoc \
+            python3-pip \
+            texinfo \
+            texlive-plain-generic
+          pip3 install md-toc --break-system-packages
+
+      - name: Build docs
+        run: |
+          make doc-regenerate

ChangeLog

@@ -1,3 +1,11 @@
+2026-02-25  Mats Lidell  <matsl@gnu.org>
+
+* .github/workflows/docs.yml: New workflow
+
+* Makefile (TEXICMD): Fail build on errors
+    (doc-clean): Use make foreach for removing doc build artifacts. (Avoid
+    bash brace expansion.) Remove README.md.html and README.toc.md.
+
 2026-02-19  Bob Weiner  <rsw@gnu.org>
 
 * hui.el (hui:link-possible-types): Fix to include link-to-wikiword only if

Makefile

@@ -129,7 +129,7 @@ EMACS = \emacs
 SITE_PRELOADS =
 
 # Command used to build the .info version of the user manual.
-TEXICMD = texi2any
+TEXICMD = texi2any --error-limit=0
 # Ensure punctuation generated by $(TEXICMD) is ascii, not unicode (requires texi2any 7.0 or above).
 TEXI2INFO = $(TEXICMD) --no-split -c ASCII_PUNCTUATION=1
 # Command used to build the .html version of the user manual.
@@ -395,9 +395,12 @@ version:
 doc: version README.md.html manual
 
 # Convenience targets for regenerating the docs
+DOC_SUFFIXES = log aux cp cpz fn fns ky toc vr vrs info pdf html
 .PHONY: doc-clean doc-regenerate
 doc-clean:
-	$(RM) man/hyperbole.{log,aux,cp*,fn*,ky*,toc,vr*,info,pdf,html}
+	$(RM) $(foreach suf,$(DOC_SUFFIXES),$(man_dir)/hyperbole.$(suf))
+	$(RM) README.md.html README.toc.md
+
 doc-regenerate: doc-clean doc
 
 # Build the Info, HTML and Postscript versions of the user manual
@@ -422,10 +425,12 @@ $(man_dir)/hyperbole.html: $(TEXINFO_SRC) $(man_dir)/hyperbole.css $(man_dir)/te
 #
 # `pandoc' is available from:
 #    https://github.com/jgm/pandoc
-README.md.html: README.md README.toc.md
+README.toc.md: README.md
 	cp -p README.md README.toc.md && md_toc -p -m [TOC] github README.toc.md \
-	  && sed -i -e 's/^\[TOC\]//g' README.toc.md \
-	  && pandoc --from=gfm-tex_math_dollars --to=html+gfm_auto_identifiers -o README.md.html README.toc.md
+	  && sed -i -e 's/^\[TOC\]//g' README.toc.md
+
+README.md.html: README.toc.md
+	pandoc --from=gfm-tex_math_dollars --to=html+gfm_auto_identifiers -o README.md.html README.toc.md
 
 # website maintenance: "https://www.gnu.org/software/hyperbole/"
 define confirm