[gnome-shell-extensions/wip/fmuellner/meson: 3/6] docs: Update instructions for extension additions for meson

[Florian Müllner <fmuellner src gnome org>]

commit b0c9fc3a3d3a5dc176637bd01ec2617bc5edf26a
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Apr 9 06:09:04 2017 +0200

    docs: Update instructions for extension additions for meson

 HACKING.md                      | 15 ++++++++-------
 extensions/meson.build.template |  5 +++++
 2 files changed, 13 insertions(+), 7 deletions(-)
---
diff --git a/HACKING.md b/HACKING.md
index 217bd50..1e5919b 100644
--- a/HACKING.md
+++ b/HACKING.md
@@ -1,13 +1,14 @@
 ## Creating a New Extension
 
 To create a new extension, add a subdirectory in extensions.
-Then create a Makefile.am like the one in example, replacing
-the EXTENSION_ID with the basename of your extension, which
-must match the UUID in metadata.json.
-If you need additional files, add them to EXTENSION_EXTRA.
-
-Then modify extensions/Makefile.am and configure.ac. It should
-be pretty self-explanatory.
+Then copy extensions/meson.build.template to meson.build in
+the new subdirectory. If you need additional sources, add
+them to extension_sources. Similarly add GSettings schemas
+to extension_schemas and other files to extension_data.
+
+Then modify the toplevel meson.build to add the new extension
+name in the appropriate set (that is one of classic_extensions,
+default_extensions or all_extensions).
 
 Don't forget to add any translatable file to po/POTFILES.in, and
 then you're done.
diff --git a/extensions/meson.build.template b/extensions/meson.build.template
new file mode 100644
index 0000000..49c09b1
--- /dev/null
+++ b/extensions/meson.build.template
@@ -0,0 +1,5 @@
+extension_data += configure_file(
+  input: 'metadata.json.in',
+  output: 'metadata.json',
+  configuration: metadata_conf
+)