Clarify the signed-off-by advice in CONTRIBUTING.md.
Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>
* Have a useful subject prefixed with the component name
(E.g.: "luci-mod-admin-full: fix wifi channel selection on multiple STA networks")
* Shortly explain the changes made and - if applicable - the reasoning behind them
-* Include Signed-off-by in the comment
+* Commit message of each commit should include a Signed-off-by line
(See <https://dev.openwrt.org/wiki/SubmittingPatches#a10.Signyourwork>)
In case you like to send patches by mail, please use the [LuCI mailinglist](https://lists.subsignal.org/mailman/listinfo/luci)