Expand GitHub Actions to Fill the release notes

Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/2937

Hopefully this works as expected in next release.

.github/workflows/main.yml

@@ -30,6 +30,10 @@ jobs:
         id: release_info
         run: |
           echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\//}
+      - name: Assemble release notes
+        run: |
+          sed -e 's/%version%/${{ steps.release_info.outputs.VERSION }}/' RELEASE.HEAD.md > release.body.txt
+          grep -m1 -B10000  "==========" CHANGELOG.md | sed -e '/==========/d' >> release.body.txt
       - name: Create GitHub release
         id: create_release
         uses: actions/create-release@v1
@@ -39,6 +43,7 @@ jobs:
           tag_name: ${{ steps.release_info.outputs.VERSION }}
           release_name: ${{ steps.release_info.outputs.VERSION }}
           prerelease: true
+          body_path: release.body.txt
       - name: Build MV2 packages
         run: |
           tools/make-chromium.sh ${{ steps.release_info.outputs.VERSION }}

CHANGELOG.md

@@ -0,0 +1,24 @@
+## New
+
+Differential update of filter lists, as a result of discussions at <https://github.com/AdguardTeam/FiltersCompiler/issues/192>. Resulting spec is [here](https://github.com/ameshkov/diffupdates).
+
+![inkscape](https://github.com/gorhill/uBlock/assets/585534/6d9fb4e2-8e33-4efe-9a65-854d125f045f)
+
+The goal is to **NOT** be ranked among the "most popular projects" by bandwidth usage (as per [jsDelivr's public stats](https://www.jsdelivr.com/statistics)):
+
+![jsDelivr stats](https://github.com/gorhill/uBlock/assets/585534/30a0522b-f9ff-4ff7-8902-6c78e0d61dd1)
+
+It is expected that differential updates will lower both requests and bandwidth usage.
+
+To benefit the much shorter update period enabled by differential updates, you must let uBO auto-update the filter lists. Forcing a manual update will prevent differential updates until the next time a list auto-update.
+
+## Fixes / changes
+
+- [Have `urltransform=` use the same syntax as `replace=`](https://github.com/gorhill/uBlock/commit/d7c99b46e6)
+- [Implement network filter option `replace=`](https://github.com/gorhill/uBlock/commit/7c3e060c01) (Firefox only because [filterResponseData](https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/API/webRequest/filterResponseData#browser_compatibility))
+- [Prevent evaluating the SNFE until fully loaded](https://github.com/gorhill/uBlock/commit/89b272775a)
+- [Add support for differential update of filter lists](https://github.com/gorhill/uBlock/commit/d05ff8ffeb)
+
+==========
+
+Older release notes go here.

RELEASE.HEAD.md

@@ -0,0 +1,12 @@
+[Commits to master since this release](https://github.com/gorhill/uBlock/compare/%version%...master)
+
+To install the developer build:
+
+- **Firefox**: Click [uBlock0_%version%.firefox.signed.xpi](https://github.com/gorhill/uBlock/releases/download/%version%/uBlock0_%version%.firefox.signed.xpi)
+    - [uBO works best on Firefox](https://github.com/gorhill/uBlock/wiki/uBlock-Origin-works-best-on-Firefox).
+- **Chromium**: Install from the Chrome Web Store (CWS): <https://chrome.google.com/webstore/detail/ublock-origin-dev-build/cgbcahbpdhpcegmbfconppldiemgcoii>.
+- **Thunderbird**: Download [uBlock0_%version%.thunderbird.xpi](https://github.com/gorhill/uBlock/releases/download/%version%/uBlock0_%version%.thunderbird.xpi), then drag-n-drop it into Thunderbird's _Add-ons Manager_ pane (Thunderbird 91+ required)
+- **Node.js**: Import from [npm](https://www.npmjs.com/package/@gorhill/ubo-core), or download and unzip [uBlock0_%version%.npm.tgz](https://github.com/gorhill/uBlock/releases/download/%version%/uBlock0_%version%.npm.tgz).
+
+---
+