Add Announcement to README

Signed-off-by: Qian Qian "Cubik"‎ <cubik65536@cubik65536.top>

README.md

@@ -8,6 +8,19 @@ macOS packaging for [ungoogled-chromium](//github.com/Eloston/ungoogled-chromium
 
 **Source Code**: It is recommended to use a tag via `git checkout` (see building instructions below). You may also use `master`, but it is for development and may not be stable.
 
+## Announcements
+
+Many people have asked for notarizing (signing) the Ungoogled-Chromium macOS build ([ungoogled-chromium#859](https://github.com/ungoogled-software/ungoogled-chromium/issues/859), [#63](https://github.com/ungoogled-software/ungoogled-chromium-macos/issues/63), [#179](https://github.com/ungoogled-software/ungoogled-chromium-macos/issues/179)).
+
+As all Ungoogled-Chromium maintainers are maintaining the software on a voluntary basis, we unfortunately do not have the funds for the Apple Developer Program membership, which is required for notarization.
+
+As of now, I, [@Cubik65536](https://github.com/Cubik65536), the maintainer of Ungoogled-Chromium macOS, am seeking sponsors to help me cover the cost of the Apple Developer Program fee. If you're interested into getting the "official" Ungoogled-Chromium macOS build notarized, please consider sponsoring me through [GitHub Sponsors](https://github.com/sponsors/Cubik65536) or [Buy me a Coffee](https://buymeacoffee.com/cubik65536).
+
+Note that:
+
+1. These sponsorship accounts are under the name of `Cubik65536`. All sponsor records (i.e. who’s sponsoring) will be public unless you choose to make it private. When sponsoring, you can leave a message specifying that it is for Ungoogled-Chromium, so you will be able to be credited in a sponsor list in the future.
+2. There are already some other volunteers who have offered notarized builds, and it is worth mentioning that there are no real differences between their build and the "official" build (released under `ungoogled-software` organization), as people behind the `ungoogled-software` organization are also all volunteers.
+
 ## Building
 
 ### Software requirements