Clarify l10n export process

docs/export-to-firefox.md

@@ -19,13 +19,15 @@ Start the system addon release process by copying the following checklist into a
   - If you've never exported to Firefox before, do `make .venv` in the Screenshots repo
   - Make sure the mozilla-central branch is checked out in your local copy of Gecko, and make sure it is up to date
   - Export changes: `EXPORT_MC_LOCATION=path/to/gecko ./bin/export_mc.py --no-commit --no-switch-branch`
-- [ ] In your copy of Gecko, double-check the diff, and commit the changes
-  - Ensure your commit message follows the [Firefox bug conventions](https://mdn.io/Committing_Rules_and_Responsibilities), for example: "Bug 1362550 - Export Screenshots 6.6.0 to Firefox; r?kmag"
+- [ ] In your copy of Gecko, double-check the diff, and split the changes into two commits: one containing any translations and any translation-related changes to the `moz.build` file, and one containing non-translation code.
+  - Ensure your commit messages follow the [Firefox bug conventions](https://mdn.io/Committing_Rules_and_Responsibilities), for example: 
+    - `"Bug 1436218 - Export Screenshots 29.0.0 to Firefox (code excluding translations); r?ianb"`
+    - `"Bug 1436218 - Export Screenshots 29.0.0 to Firefox (translations only); r?ianb"`
   - Choosing reviewers:
-    - For all exports, r? a [Screenshots owner or peer](https://wiki.mozilla.org/Modules/All#Screenshots) (currently ianb or 6a68)
-    - For translation-only changes, r? the [l10n driver for Firefox](https://wiki.mozilla.org/L10n:Mozilla_Team) (currently flod)
-    - For changes to chrome-privileged code or security-sensitive content script code, r? a [Firefox peer](https://wiki.mozilla.org/Modules/All#Firefox) (suggested: kmag or mossop)
-    - For changes to screenshots UI code not inside a content script, optionally r? a Firefox peer
+    - For all changes, r? a [Screenshots owner or peer](https://wiki.mozilla.org/Modules/All#Screenshots) (currently ianb or 6a68)
+    - For translation-only changes, also r? the [l10n driver for Firefox](https://wiki.mozilla.org/L10n:Mozilla_Team) (currently flod)
+    - For changes to chrome-privileged code or security-sensitive content script code, also r? a [Firefox peer](https://wiki.mozilla.org/Modules/All#Firefox) (suggested: kmag or mossop)
+    - For changes to screenshots UI code not inside a content script, also r? a Firefox peer if the additional review seems warranted
     - This guidance may change in the future. Last communication on this topic: [bug 1412091 comment 6](https://bugzilla.mozilla.org/show_bug.cgi?id=1412091#c6)
 - [ ] Push the changes to the Try server
   - Suggested incantation: `./mach try -b o -p linux64,macosx64,win32,win64 -u all -t all --rebuild-talos 5 --no-artifact`