Editorial: Update docs with PR label guidance (#2317)

documentation/process.md

@@ -19,6 +19,7 @@ Newly opened PRs are "triaged" at the next ARIA meeting. At triage, it is decide
 Draft PRs are not triaged at meeting and are considered not read for review. If you want to prevent an approved PR from getting merged, add the `do not merge` label.
 
 PR Labels:
+- `spec:aria`, `spec:accname`, `spec:core-aam`, `spec:html-aam`, `spec:<spec-short-hand>` should be used for all specs which have changes in this PR. 
 - `waiting for implementations`: if a normative PR has been approved but there are no implementations yet, then use this flag to indicate it can be merged when the implementations are completed.
 - `do not merge`: if a PR has approving reviews but there is some reason to wait for merging.
 
@@ -76,4 +77,4 @@ Important branches in the ARIA repository:
 The "normative change checklist" list a kind of "to do list" for all the work that must happen in order for a change to be considered ready for merge. Check the box when there is a relevant issue or PR related to the item in the list, and link the relevant issue or PR. Some of the things in the list may not apply to your change, if they don't apply, check the box and write "n/a". If you aren't sure whether something applies, leave it unchecked.
 
 The normative change checklist should be included in the PR template when you open a PR, if for some reason it is missing, you can copy it into the description of the PR:
-[Normative Change Checklist](https://github.com/w3c/aria/blob/main/.github/pull_request_template.md).
+[Normative Change Checklist](https://github.com/w3c/aria/blob/main/.github/pull_request_template.md).