Editorial: Move this spec to ARIA monorepo (#548)

Author: spectranaut

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,17 +1,9 @@
-# HTML-AAM
+# Specification 'html-aam'
 
-*****
- PLEASE NOTE
+This is the issue tracking repository for HTML Accessibility API Mappings (html-aam). You can read the [Editor's Draft version of the specification here](https://w3c.github.io/html-aam/).
 
- The files for this spec are now being updated in the ARIA repository: https://github.com/w3c/aria/tree/main/html-aam
+You can also compare against [the most recent published version here](https://www.w3.org/TR/html-aam-1.0/).
 
- All new updates need to be made in those files.
-
- Please do not make new PRs against this repository. 
-*****
-
-
-HTML Accessibility API Mappings (html-aam) developed by the [Accessible Rich Internet Applications Working Group](https://www.w3.org/WAI/ARIA/) (previously the [Web Applications Working Group](https://www.w3.org/2019/webapps/)). It is the basis of the [Editor's Draft version of the specification](https://w3c.github.io/html-aam/).  You can also compare against [the most recent published version](https://www.w3.org/TR/html-aam-1.0/).
-
-This specification was part of the [ARIA suite](https://www.w3.org/WAI/ARIA/deliverables). General information about editing the specification is in the [main ARIA repository readme](https://github.com/w3c/aria/).
+To open a PR, please see the [main ARIA repository where the specification lives](https://github.com/w3c/aria/html-aam). This specification is part of the [ARIA suite](https://www.w3.org/WAI/ARIA/deliverables), and uses the same code structure and build tools as other ARIA suites. General information about editing specifications is in the [main ARIA repository readme](https://github.com/w3c/aria/).
 
+This specification was previously developed by the [Web Applications Working Group](https://www.w3.org/2019/webapps/)