[Editorial] Move spec files to root directory and remove unused files

.github/workflows/generate.yml

@@ -14,7 +14,7 @@ jobs:
         with:
           GH_PAGES_BRANCH: gh-pages
           TOOLCHAIN: bikeshed
-          SOURCE: docs/index.bs
-          DESTINATION: docs/index.html
+          SOURCE: index.bs
+          DESTINATION: index.html
           VALIDATE_MARKUP: true
           BUILD_FAIL_ON: fatal

.pr-preview.json

@@ -1,5 +1,5 @@
 {
-  "src_file": "docs/index.bs",
+  "src_file": "index.bs",
   "type": "bikeshed",
   "params": {
     "force": 1

README.md

@@ -16,7 +16,7 @@ Spec development happens via [issues in this repository](https://github.com/w3c/
 
 Updates to the spec must reference [resolved issues marked `needs spec`](https://github.com/w3c/ServiceWorker/issues?q=is%3Aclosed+label%3A%22needs+spec%22).
 
-To make edits to the design, please send pull requests against the Nightly spec on the master branch. We use [bikeshed](https://github.com/tabatkins/bikeshed). So, change `docs/index.bs` and submit it with the corresponding bikesheded `index.html`.
+To make edits to the design, please send pull requests against the Nightly spec on the master branch. We use [bikeshed](https://github.com/tabatkins/bikeshed). So, change `index.bs` and submit it with the corresponding bikesheded `index.html`.
 
 ## Examples