Trimmed set of translations built by default.

Only translations touched the last 12 months or where >= 2% of the strings
are translated according to Weblate get build rules in docs/src/Submakefile, and
only languages with >50% get Debian packages with the translations.  The new
guidelines are documented in docs/README.adoc.

The set of translations built and published on https://linuxcnc.org/docs/devel/html/
are now Arabic, German, Spanish, French, Norwegian Bokmål, Russian, Swedish, Turkish
and Simplified Chinese.  Hungarian and Vietnamese are no longer built.  Reduced the
list in index.html to the built ones.

Debian packages for French, Spanish and Simplified Chinese are no longer created.

debian/control.docs.in

@@ -27,53 +27,3 @@ Description: motion controller for CNC machines and robots (English documentatio
  applications (milling, cutting, routing, etc.).
  .
  This package contains the documentation in English.
-
-Package: linuxcnc-doc-fr
-Provides: linuxcnc-doc
-Architecture: all
-Multi-Arch: foreign
-Depends: ${misc:Depends}
-Breaks: linuxcnc-uspace (<= 2.9.0~pre0+git20220402.2500863908-4)
-Replaces: linuxcnc-uspace (<= 2.9.0~pre0+git20220402.2500863908-4)
-Recommends: xdg-utils
-Suggests: pdf-viewer
-Description: motion controller for CNC machines and robots (French documentation)
- LinuxCNC is the next-generation Enhanced Machine Controller which
- provides motion control for CNC machine tools and robotic
- applications (milling, cutting, routing, etc.).
- .
- This package contains the documentation in French.
-
-Package: linuxcnc-doc-es
-Provides: linuxcnc-doc
-Architecture: all
-Multi-Arch: foreign
-Depends: ${misc:Depends}
-Breaks: linuxcnc-uspace (<= 2.9.0~pre0+git20220402.2500863908-4)
-Replaces: linuxcnc-uspace (<= 2.9.0~pre0+git20220402.2500863908-4)
-Recommends: xdg-utils
-Suggests: pdf-viewer
-Description: controlador de movimiento para máquinas CNC y robots (Español).
- LinuxCNC es EMC (controlador de máquina mejorado) que proporciona
- control de movimiento para máquinas herramientas CNC (fresado,
- torneado, ruteado, etc.) y aplicaciones de robótica.
- .
- Este paquete contiene la documentación en español.
-
-Package: linuxcnc-doc-zh-cn
-Provides: linuxcnc-doc
-Architecture: all
-Multi-Arch: foreign
-Depends: ${misc:Depends}
-Recommends: xdg-utils
-Suggests: pdf-viewer
-Conflicts: linuxcnc-doc-cn
-Replaces: linuxcnc-doc-cn
-Description: motion controller for CNC machines and robots (Chinese
- documentation)
- LinuxCNC is the next-generation Enhanced Machine Controller which
- provides motion control for CNC machine tools and robotic
- applications (milling, cutting, routing, etc.).
- .
- This package contains the documentation in Chinese.
-

debian/rules.in

@@ -113,17 +113,12 @@ override_dh_installdocs-indep:
 	dh_installdocs --doc-main-package=@MAIN_PACKAGE_NAME@ --package=linuxcnc-doc-en
 	mv debian/linuxcnc-doc-en/usr/share/doc/@MAIN_PACKAGE_NAME@ debian/linuxcnc-doc-en/usr/share/doc/linuxcnc
 
-	dh_installdocs --doc-main-package=@MAIN_PACKAGE_NAME@ --package=linuxcnc-doc-es
-	mv debian/linuxcnc-doc-es/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode.html debian/linuxcnc-doc-es/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode_es.html
-	mv debian/linuxcnc-doc-es/usr/share/doc/@MAIN_PACKAGE_NAME@ debian/linuxcnc-doc-es/usr/share/doc/linuxcnc
+# Remove files for translations created where we do not want Debian packages.
+	for l in ar es fr ru zh_CN; do \
+		$(RM) debian/tmp/usr/share/doc/linuxcnc/LinuxCNC_*_$$l.pdf; \
+	done
+	$(RM) debian/tmp/usr/share/doc/linuxcnc/*_es.adoc
 
-	dh_installdocs --doc-main-package=@MAIN_PACKAGE_NAME@ --package=linuxcnc-doc-fr
-	mv debian/linuxcnc-doc-fr/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode.html debian/linuxcnc-doc-fr/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode_fr.html
-	mv debian/linuxcnc-doc-fr/usr/share/doc/@MAIN_PACKAGE_NAME@ debian/linuxcnc-doc-fr/usr/share/doc/linuxcnc
-
-	dh_installdocs --doc-main-package=@MAIN_PACKAGE_NAME@ --package=linuxcnc-doc-zh-cn
-	mv debian/linuxcnc-doc-zh-cn/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode.html debian/linuxcnc-doc-zh-cn/usr/share/doc/@MAIN_PACKAGE_NAME@/gcode_zh_CN.html
-	mv debian/linuxcnc-doc-zh-cn/usr/share/doc/@MAIN_PACKAGE_NAME@ debian/linuxcnc-doc-zh-cn/usr/share/doc/linuxcnc
 
 
 override_dh_compress:

docs/README.adoc

@@ -183,7 +183,18 @@ the translation level raise to a sensible level (for example not 0%),
 build rules need to be added to use the generated translations to
 build HTML and PDF editions of the translation.
 
-Add the new language code to the proper place in docs/po4a.cfg.
+At the moment, build rules are created for languages with more than 2
+percent translated
+link:https://hosted.weblate.org/projects/linuxcnc/linuxcnc-docs/[according
+to Weblate] or which have been updated the last 12 months according to
+the PO-Revision-Date field in docs/po/*.po.  Documentaion packages for
+Debian are build for languages with more than 50 percent translation.
+This ensure translators and proof readers can see the result of their
+effort on https://linuxcnc.org/docs/devel/html/, while we limit the
+time spent building translations to those that are actively worked on
+or at least have a very the bare minimum translated.
+
+Add the new language code to the [po4a_langs] section of docs/po4a.cfg.
 Update build rules for the new language in `docs/src/Submakefile`.
 
 Edit debian/control.in to add the new linuxcnc-doc-$NEWLANG package.