Add a 'release' target to generate a ready to install tarball

meson.build

@@ -70,3 +70,17 @@ gstreamer_doc = hotdoc.generate_doc('GStreamer',
     build_always_stale: true,
     edit_on_github_repository: 'https://gitlab.freedesktop.org/gstreamer/gst-docs/',
 )
+
+cdata = configuration_data()
+cdata.set('GST_API_VERSION', apiversion)
+readme = configure_file(input: 'scripts/RELEASE_README.md',
+               output: 'README.md',
+               configuration : cdata)
+
+run_target('release',
+  command: [find_program('scripts/release.py'),
+            gstreamer_doc.full_path(),
+            'GStreamer-doc-@0@.tar.xz'.format(meson.project_version()),
+            join_paths(meson.current_build_dir(), 'README.md')],
+  depends: [gstreamer_doc]
+)

scripts/RELEASE_README.md

@@ -0,0 +1,10 @@
+# GStreamer documentation
+
+This is the released version of the [GStreamer documentation](https://cgit.freedesktop.org/gstreamer/gst-docs), it contains
+two folders:
+
+* html/: The static website documentation which can be hosted anywhere and
+         read in any web browser.
+* devhelp/: The documentation to be browsed with [devhelp](https://wiki.gnome.org/Apps/Devhelp).
+            The content of that folder should be installed in `/usr/share/gtk-doc/html/GStreamer-@GST_API_VERSION@/`
+            by documentation packages.

scripts/release.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+
+import os
+import sys
+import tarfile
+
+if __name__ == "__main__":
+    files = sys.argv[1]
+    outname = sys.argv[2]
+    readme = sys.argv[3]
+
+    tar = tarfile.open(outname, 'w:xz')
+    os.chdir(files)
+    tar.add(os.path.curdir)
+    os.chdir(os.path.dirname(readme))
+    tar.add(os.path.basename(readme))
+    tar.close()