Updated the reference to /allow to use implicit username

logiclrd · logiclrd · commit fe5567aae09e · 2019-10-26T17:12:17.000-05:00
@webstech (GitHub) pointed out that /allow can be used without specifying a username, in which case the PR author is added to the allowed list. Updated the wording to use this implicit form, and to emphasize that it should be done on one of the user's own PRs.
diff --git a/res/WELCOME.md b/res/WELCOME.md
@@ -15,7 +15,7 @@ It is in general a good idea to await the automated test ("Checks") in this Pull
 
 ## Contributing the patches
 
-Before you can contribute the patches, your GitHub username needs to be added to the list of permitted users. Any already-permitted user can do that, by adding a PR comment of the form `/allow <username>`. A good way to find other contributors is to locate recent pull requests where someone has been `/allow`ed:
+Before you can contribute the patches, your GitHub username needs to be added to the list of permitted users. Any already-permitted user can do that, by adding a comment to your PR of the form `/allow`. A good way to find other contributors is to locate recent pull requests where someone has been `/allow`ed:
 
 * [Search: is:pr is:open "/allow"](https://github.com/gitgitgadget/git/pulls?utf8=%E2%9C%93&q=is%3Apr+is%3Aopen+%22%2Fallow%22)
 
